G15T8 UV GERMICIDAL bulb replacement lamp. is 15 watts and 436mm in length. See document below for a complete list of equipment brands and models using the G15T8 lamp.
Germicidal lamp peak wavelength: 253.7nm. Total UV output: 18 watts. Cross reference: Ushio (3000316); GE (15875); Laguna Power Max 5000, PT1660, PT1661, Hagen Power Clear; Osram Sylvania (23388)."