The Hi-Tech Lamps part number F18T8/BLB-U is a 18 watt (18W), 57 volt (57V) UVA Blacklight Blue Lamp made by Ushio. This lamp has a 25.5mm diameter and an overall length (excluding base pins) of 588.5mm with G13 bi-pin bases. This UVA Blacklight Blue Lamp has an average life of 4000 hours. It has an initial UV output of 3.7 watts, with a spectral peak at 368 nanometers (368nm). This lamp is also known as Ushio F18T8BLB, F18T8/BLB and 3000307.