Olympus FL-50 electronic flash. I'm selling this unit because I thought I was going to get into photography and never did anything with it. The flash was rarely used, and has just been sitting in a box in the closet for the past few years. It has a few minor scratches on it from when I took it on a couple of trips a few years back, but other than that, the bulb itself has hardly been used. I bought it for an Olympus E-series camera. I have no idea what other cameras it's compatible with. A real photographer would know more than I would.