20KM Visual Fault Locator Laser Pen Price in Kenya

A 20KM Visual Fault Locator Laser Pen is a portable fibre optic testing tool used to trace fibre routes, verify continuity and visually locate breaks, sharp bends, faulty connectors and poor splices. It works by injecting visible red laser light into the fibre so that severe losses or physical faults can be seen as glowing or flashing red light along the cable path. 

Typical 20KM pen-style VFLs use a 650nm red laser with about 20mW output power. Published specifications for this class of tester show a single-mode range of around 15–20 km, while multimode visible range is usually much shorter. Many models also provide both continuous-wave and pulsed operation for easier fibre identification.

Key Specifications

A representative 20mW unit specifies 650nm wavelength, >15–20 km single-mode range, >5 km multimode range, CW and pulsed modes and a universal 2.5mm connector. 

What Is a 20KM Visual Fault Locator?

A Visual Fault Locator, or VFL, is a visible optical source used to troubleshoot fibre without requiring a full OTDR setup.

The basic method is:

VFL → Fibre Connector → Fibre Cable → Visible Fault

If light escapes at a severe bend, break or poor joint, the technician can visually identify the problem.

This makes a VFL particularly useful for short and medium fibre runs, patch cords, FTTH subscriber drops and fibre identification.

Why 20KM?

The “20KM” designation generally refers to the manufacturer's nominal maximum visible tracing range under favourable conditions, usually on single-mode fibre.

A common power-to-range classification is:

This type of classification appears in current VFL technical documentation. 

Actual visible reach depends on fibre attenuation, connectors, splitters, cable construction, bends and ambient light.

650nm Red Laser

The 20KM VFL typically uses a 650nm visible red laser. 

The visible wavelength allows faults to be identified without specialized infrared viewing equipment.

Continuous and Pulsed Modes

Most professional pen-style VFLs provide:

• CW / continuous light

• Pulsed / flashing light

Pulsed mode can make a particular fibre easier to identify when several fibres are present inside an ODF or distribution box. 

2.5mm Universal Connector

A common 20KM VFL uses a 2.5mm universal optical interface. 

This works directly with connectors such as:

• SC

• FC

• ST

For LC connectors, a 1.25mm adapter is usually required.

How a Visual Fault Locator Finds Fibre Breaks

When red laser light reaches a severe fibre defect, some of the light can escape through the glass and jacket.

Visible red light may indicate:

• Fibre break

• Tight bend

• Cracked fibre

• Poor mechanical splice

• Faulty connector

• Damaged patch cord

• Incorrect route

This makes the tool especially convenient for visual troubleshooting.

FTTH Applications

A typical FTTH link may be:

OLT → ODF → Feeder Fibre → PLC Splitter → FAT Box → Drop Cable → ATB → ONU

The VFL can help test sections such as:

• Patch cord

• Pigtail

• Drop cable

• FAT-to-subscriber connection

• ATB termination

• Short distribution fibre

Using a VFL on FTTH Drop Cable

A technician can connect the VFL at one end and inspect the route for visible leakage.

This can help detect:

• Drop cable bent around corners

• Damaged fibre at cable clips

• Breaks caused during installation

• Faulty fast connectors

• ATB termination problems

Using a VFL in an ODF

Inside an Optical Distribution Frame, a VFL can help:

• Identify the correct pigtail

• Trace fibre routing

• Verify continuity

• Check patching

• Locate severe bends

• Confirm fibre mapping

Pulsed mode can make identification easier where many fibres are present.

Using a VFL in FAT Boxes

Inside a Fibre Access Terminal box, a VFL helps technicians trace subscriber fibres and confirm which port belongs to a specific customer.

This is especially helpful during:

• New subscriber activation

• Fibre repair

• Port identification

• Drop cable troubleshooting

Using a VFL on Patch Cords

Patch cords often fail near the connector boot because of repeated bending or pulling.

A VFL can help identify:

• Broken internal fibre

• Severe bends

• Damaged connector areas

• Poorly terminated jumper fibres

Single-Mode and Multimode Testing

A 20KM VFL can be used on both single-mode and multimode fibre.

However, range is not the same.

A representative 20mW unit lists >15–20 km on single mode and >5 km on multimode. 

Watch 20KM Visual Fault Locator Laser Pen

https://youtu.be/IKEwZRtFRE0

The 20KM Visual Fault Locator Laser Pen is useful because it provides a fast visual check before technicians move to more advanced equipment. If a customer has no signal, for example, the VFL can quickly help determine whether a drop cable or patch cord has suffered an obvious physical fault.

Its pen-style format also makes it easy to carry alongside a fibre cleaver, stripper, Optical Power Meter and fusion splicer. Many 20mW designs use rugged aluminium-alloy housings and battery operation specifically for field technicians. 

For a complete testing workflow, a VFL should be used together with an Optical Power Meter, PON meter or OTDR when quantitative loss measurements or exact fault distances are required.

VFL vs Optical Power Meter

VFL vs OTDR

An OTDR provides much more detailed information, while the VFL is faster for basic visual troubleshooting.

VFL vs PON Power Meter

10mW vs 20mW VFL

For everyday subscriber FTTH work, 10mW may already be sufficient. A 20mW VFL provides additional power where longer-distance visual tracing is desired.

How to Use a 20KM Visual Fault Locator

1. Confirm the fibre is safe to test.

2. Clean the fibre connector.

3. Remove the VFL protective cap.

4. Insert the fibre connector.

5. Switch the VFL on.

6. Select continuous or pulsed mode.

7. Trace the fibre route.

8. Look for escaping red light.

9. Inspect connectors and bends.

10. Switch the VFL off after testing.

11. Replace its dust cap.

Visual Fault Locator Safety

A 20mW VFL is a high-powered visible laser, not a harmless flashlight.

Never:

• Look directly into the laser aperture.

• Look into the end of a connected fibre.

• Aim the laser at another person's eyes.

• Use a microscope or magnifier on an active VFL-connected fibre.

• Leave the laser running unnecessarily.

The higher output used for long-range tracing makes eye safety particularly important.

Fibre Testing Tool Combination

A professional FTTH technician may carry:

Visual Fault Locator Price in Kenya

The 20KM Visual Fault Locator price in Kenya varies depending on:

• Output power

• Brand

• Rechargeable vs replaceable batteries

• Housing quality

• Connector adapter

• Included case

• Warranty

• Build quality

The main thing to confirm is that the product is a genuine 20mW-class VFL, rather than assuming every product labelled “20KM” has the same optical power.

Recommended Accessories

Frequently Asked Questions

What is a 20KM Visual Fault Locator?

It is a fibre testing pen that injects visible red laser light into optical fibre to help locate faults and trace fibre routes.

What output power does a typical 20KM VFL use?

A common 20KM model uses approximately 20mW output. 

What wavelength does it use?

Typical units operate around 650nm. 

Can it really test 20 km?

Manufacturers commonly rate 20mW units at around 15–20 km on single-mode fibre under favourable conditions. Actual visible reach varies. 

Can it test multimode fibre?

Yes, but the visible range is generally much shorter. One 20mW specification lists more than 5 km for multimode compared with 15–20 km for single mode.

Does it support continuous light?

Yes.

Does it support flashing light?

Yes. CW and pulsed operation are common. 

What connector does it use?

Most use a 2.5mm universal optical connector. 

Can it connect directly to SC?

Yes.

Can it connect to FC?

Yes.

Can it connect to ST?

Yes.

Can it connect to LC?

Usually with a 1.25mm adapter.

Can it test SC/APC?

Yes, provided the ferrule fits the universal interface.

Can it test SC/UPC?

Yes.

Can it find fibre breaks?

Yes, especially where visible red light can escape from the damaged section.

Can it identify sharp bends?

Yes.

Can it test patch cords?

Yes.

Can it test pigtails?

Yes.

Can it test FTTH drop cable?

Yes.

Can it be used inside an ODF?

Yes.

Can it be used in FAT boxes?

Yes.

Can it be used with fibre closures?

Yes.

Can it identify one fibre among many?

Yes. Pulsed mode can make tracing easier.

Can it measure optical power?

No. Use an Optical Power Meter.

Can it tell me the exact distance to a fault?

No. Use an OTDR.

Can it measure splice loss?

No. An OTDR or suitable loss-test setup is required.

Can it replace an OTDR?

No.

Can it replace a PON Power Meter?

No.

Does the VFL need batteries?

Yes. Many 20mW pen-style models use two AA or AAA batteries, depending on design. 

Is the housing metal?

Many professional pen-type VFLs use aluminium-alloy housings. 

Is 20mW stronger than 10mW?

Yes.

Is a 20mW VFL safe to look into?

No. Never look directly into the laser or connected fibre.

Should I use a microscope to inspect a fibre connected to a VFL?

No.

Is a VFL useful for FTTH technicians?

Yes. It is one of the quickest tools for continuity and visible fault checks.

Is it suitable for ISPs?

Yes.

Is it useful during emergency fibre repairs?

Yes.

Do you supply 20KM Visual Fault Locators?

Yes. Fiber Optics Kenya can supply Visual Fault Locator laser pens and related fibre testing tools.

Do you supply 10mW VFLs?

Yes.

Do you supply Optical Power Meters?

Yes.

Do you supply PON Power Meters?

Yes.

Do you supply OTDRs?

Yes.

Do you supply fusion splicing machines?

Yes.

Do you supply fibre cleavers?

Yes.

Do you deliver outside Nairobi?

Yes. Fiber Optics Kenya supplies fibre optic equipment throughout Kenya.

Why Buy a 20KM Visual Fault Locator from Fiber Optics Kenya?

Contact Fiber Optics Kenya

Fiber Optics Kenya
Lyric House, 7th Floor Room S9
Kimathi Street, Nairobi

Phone: +254 704 991 492
Email: info@fibreopticskenya.co.ke

The 20KM Visual Fault Locator Laser Pen is a practical testing tool for FTTH installers, ISPs, fibre contractors and telecom technicians who need to trace fibre and identify visible physical faults quickly. Typical 20KM units use a 20mW, 650nm red laser, provide both continuous and pulsed operation and use a universal 2.5mm connector for common SC, FC and ST interfaces. 

Its compact pen-style design makes it suitable for patch cords, pigtails, ODFs, FAT boxes, subscriber drop cables and short-to-medium fibre troubleshooting. However, the quoted 20 km range should be treated as a nominal single-mode rating rather than a guarantee under every network condition.

Contact Fiber Optics Kenya for 20KM Visual Fault Locator Laser Pen prices in Kenya, 10mW and 20mW VFLs, Optical Power Meters, PON Power Meters, OTDRs, fusion splicers, fibre cleavers, complete FTTH testing kits, bulk orders and nationwide delivery.