The MaxTester 715B from EXFO Inc. is a Optical Time Domain Reflectometer (OTDR) with OTDR Measurement Time User-defined, Event Dead Zone 1 m, Attenuation Dead Zone 4 m, Optical Wavelength 1310 to 1625 nm, Dynamic Range 28 to 30 dB. More details for MaxTester 715B can be seen below.