This fiber optic Variable Attenuator uses collimator lens technology, enabling you to change attenuation by .5dB increments by simply twisting a top mounted screw. This type of variable attenuator is useful for many applications. For example, it can simulate the loss in a fiber optic system, or it can be used to test your system's dynamic range. The attenuation range of this device is 0.8dB to 80dB. You can use a power meter and light source to determine the actual attenuation value that your system requires. This attenuator has a 0.8dB typical insertion loss and is available in 2 meter singlemode cable lengths, which you can terminate with your own connector types according to your system requirements. A low back reflection style is also available, which is pre-terminated with ultra PC connectors to maintain the internal low back reflection characteristics of this attenuator.