Portable and lightweight. For identifying fluorescent paper (tagging) on stamps of Canada, China, France, Mexico, etc. Also for verifying inks, colors, forgeries, and repairs. Check for quality and authenticity of coins, banknotes, certificates, artwork, etc. Nylon strap is attached for easy carrying. Operates on 4 "AA" batteries (included). Supplied with 4 Watt ultraviolet lamp. The wavelength is 366nm (nanometers). Size: 6-3/8" x 2" x 7/8" high.