The TB6000AV2 from Viavi Solutions Inc. is a Optical Time Domain Reflectometer (OTDR) with Event Dead Zone 0.2 to 0.25 m, Attenuation Dead Zone 0.4 to 2.1 m, Optical Wavelength 850 to 1300 nm, Dynamic Range 16 to 24 dB, Pulse Width 1 ns. More details for TB6000AV2 can be seen below.