EFB Elektronik 399900.2 Fibre Light Coupler

The EFB Elektronik 399900.2 light injector is a compact visual fault locator designed for field, industrial and laboratory fiber optic applications. It emits visible red light in the 630–670 nm range to help locate breaks and faults in singlemode and multimode fiber cables. The unit supports common ferrule sizes and connector types and is supplied with a dust cover and adapters; batteries are not included.

Advantages

The device provides a visible red light source for quick detection of fiber faults up to a range of approximately 6 km. Its small size and support for multiple connector ferrules (2.5 mm: DIN, E2000®, FC, SC, ST; 1.25 mm: LC) make it versatile for a variety of test and maintenance tasks. The injector is suitable for both laboratory and on-site troubleshooting and patching.

Suitable for

• Testing singlemode and multimode fiber optic cables
• Locating breaks and faults in fiber runs
• Identifying and patching individual fibers in bundles or panels
• Field testing, industrial maintenance, and laboratory verification

Key specifications

• Manufacturer: EFB Elektronik
• Model / MPN: 399900.2
• Wavelength: 630–670 nm (visible red)
• Maximum range: up to 6 km (approx.)
• Supported ferrules/connectors: 2.5 mm (DIN, E2000®, FC, SC, ST); 1.25 mm (LC)
• Dimensions: 113 mm x 34 mm x 20 mm
• Power: AAA batteries (not included)
• Included accessories: dust cover, adapter for LC, SC and FC
• EAN: 4049759210816

How to use

Install the required AAA batteries, attach the appropriate adapter or connector to match the fiber under test, and switch on the unit to emit visible red light. Connect the injector to the fiber endface and observe the light to locate breaks, bad splices, or identify individual fibers. For long runs, verify the visibility by inspecting intermediate connection points and use the dust cover when the device is not in use.

Recommendations

Do not look directly into the light source. Use compatible adapters to avoid damaging connector endfaces and always keep the dust cover on when storing the unit. Replace batteries before long test sessions to ensure consistent output.