The G10T5/4P is a 16 watt preheat start, ozone free Germicidal (AKA 254nm or UVC ) Lamp with 5.3 Watts UV. Typical lifetime is 9000 hours. This lamp has one G10Q 4 pin base on the 15.5mm diameter x 357mm 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, UVP, American Ultraviolet, among many others, as part numbers 23385, G10T5/4P/SE/OF, GPH10T5L, G10T5, LS400/CB, GPH357T5L-7, LS400 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.