This is a light meter I used until a few years ago. It's a rare item now. I'm selling it because I no longer use it. Main Features and Functions: Purpose: Compatible with strobe light and continuous light. Suitable for precise exposure settings in studio strobe photography. Operability: Compact size that can be operated with one hand. One-touch switching between incident and reflected light metering. Power: Uses one AA battery, which is easy to obtain and replace.