Looking for a value driven, alternative solution to your name brand "factory" replacement UV lamp and sleeve US Water Filters replacement lamps and sleeves are made in the US to the exact same stringent manufacturing protocols, and are backed by a one-year, no-hassle warranty. The USWF-112045 is a replacement for VIQUA 602810-103 Lamp/Sleeve replacement combo pack used in the VIQUA E4, E4+, E4-V, E4-V+, E4-50+, IHS22-E4 systems and the discontinued Trojan PRO7 system. The UV lamp needs replacement every 12 months. After 10,000 hours the UV light weakens and isnt strong enough to properly treat your water. Replacing your lamp annually to ensure optimal system performance. The quartz sleeve is an important part of the UV water treatment system. It protects the UV lamp from coming in contact with the water while allowing the UV light to penetrate the water. Minerals from the water will build up on the sleeve over time causing the sleeve to become cloudy not allowing the UV light to penetrate the water as effectively. Once the mineral layer on the quartz sleeve cannot be removed via cleaning, or the sleeve cracks or breaks its time to get a replacement. USWF-112045 includes the USWF-140112 lamp, USWF-350045 sleeve, and 4 extra o-rings to ensure you can replace the o-rings after every cleaning and lamp replacement. Safety Note: NEVER look directly at the UV lamp when it is powered on. Follow the instructions carefully to avoid injury to eyes and skin.