The G22T5/4P is a 22 watt preheat start, ozone free Germicidal (AKA 254nm or UVC ) Lamp with 6 Watts UV. Typical lifetime is 9000 hours. This lamp has one G16qA 4 pin base on the 15.5mm diameter x 436mm long (excluding pins) clear T5 tube. This item is Made in Japan by Sankyo-Denki, and is also commonly available from Philips, Osram-Sylvania, GE, Ushio, American Ultraviolet, among many others, as part numbers GPH436T5L/4, GPH436T5L/4P, GPH435T5L/4, GPH435T5L/4P G22T5L/SP, 3000350, and many more. Product Warning: Germicidal lamps emit harmful ULTRAVIOLET RADIATION (UVC). Avoid direct or reflected exposure as this can cause serious skin burns and eye injury. This lamp SHOULD NOT BE USED FOR ILLUMINATION PURPOSES. Skin and eye protection should be worn at all times when operating.