Trojan 602805 Compatible UV Lamp for UV MAX C, D, C4, D4 + Ultraviolet Water Sterilizer Systems Highest Quality 602805 Compatible UV Lamp Matches OEM Specifications 100% 43W Length is Approximately 15 -1/2" ExactFit UV is the leader in aftermarket UV Replacement Industry. This is not a Trojan Branded Bulb.