You are offerding on a new single mode fiber optical Tap-Integrated Photo Detector made by Hitachi Metals, model number P135-0-01. It has a photo detector to measure the 5% tap power from the integrated filter inside the device in the 1550nm band. The remaining power is reflected back to the output fiber. The IPD (integrated photo detector) is very compact and is easily mounted on a PCB for system use. Optical properties are excellent and include a broad wavelength range covering C -band with low insertion loss and high sensitivity.