New, old stock Motorola part number MFOD1100 high speed Silicon (Si) PIN photodiode. This detector has a ball lens on the detector surface to couple light from a fiber optic.  It has a spectral response range of 350 to 1100 nm with a peak response at about 900 nm. Comes with a plastic alignment bushing pn:MFOA06 for installation into a fiber optic connector type (AMP #228765, Amphenol #905-138-5001).

The spec sheet is available here: MFOD1100SPECS