The Tektronix OF150, introduced in 1983, is a fiberoptic time-domain reflectometer (TDR) operating at 820/850 nm wavelength for multimode fibers.
The OF152, introduced in 1985, is the same for 1300 nm multimode, and the OF-151, introduced in 1986, is the 1300 nm singlemode model.
In addition to the CRT, the OF15x series has an LCD for distance readout.
OF151 Opt. 04