I didn't remember it but my friend has told me it is 254 nanometres, and acording to him is the exact wave length for this TLC. Plates are Merck silica gel 60 F 254 (yes, 254, the wave length). The disco and money uv light is around 350, and we compared both in a TLC and the money one showed no more than normal light. The invention is that is armed in the money detect apparatus, very nice.