The G55T8 is a 55 watt preheat start, ozone free Germicidal (AKA 254nm or UVC ) Lamp with 18 Watts UV. Typical lifetime is 8000 hours. This lamp has two G13 (medium bi-pin) bases on the 25.5mm diameter x 893mm long (excluding pins) clear T8 tube. This item is made by Osram-Sylvania, and is also commonly available from Philips, Sankyo-Denki, GE, Ushio, American Ultraviolet, among many others, as part numbers 15875, G55T8HO, 23388, G55T8/OF, TUV55W/HO, 3000316, 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.