I bought this for a job installing fiber optic mesh. I use it as a tracer to find my PFP port. It's much lighter than what my job gave me and I can easily find port. Even on a bright sunny day, I can easily find my port.
Pros
WIDELY USED: 2.5mm universal socket test for singlemode and multimode fiber optic cable with ST/SC/FC interface, red light output distance 8-10km, replaceable ceramic core. Extended life design