The Hamamatsu H10722-20 photosensor module is compatible with our cubes and is the most sensitive detector we offer for very low light level detection. Unlike other ports of our mini cubes that have receptacles and focusing lens, the port for this sensor has a lens that adjust the beam size to fit the size of PMT and instead of receptacle it has a thread that matches the thread on doric adapter for the photosensor. The photomultiplier tube (PMT) is highly sensitive and can be easily damaged if exposed to high optical power. The photosensor module requires a power supply model C10709.