The YSU1315 from Tektronix is a Optical Time Domain Reflectometer (OTDR) with Event Dead Zone 2 m, Attenuation Dead Zone 8 m, Optical Wavelength 1310 to 1550 nm, Dynamic Range 44 dB, Pulse Width 2 to 20 µs. More details for YSU1315 can be seen below.