I have used this to test fiber, mainly singlemode but also multimode. I ended up using the RJ45 test features more often than I thought I would. This meter is accurate and just works. The battery lasts a long time (weeks) and has already paid for itself 100 times. The other guys at work always ask me to borrow this meter, we have 3 other kits to test fiber with other meters and this is by far the most popular.