Please Note: This purchase is for the sleeve only and does NOT include the bulb (also pictured) The Pondmaster 10W UV Replacement Quartz Sleeve is specifically designed for the Pondmaster 10W UV Sterilizers and Pondmaster Pressure Filters with 10W UV Sterilizers. This bulb is made of quality components and is 10 inches long! The 10W UV Replacement Quartz Sleeve ensures that your bulb is protected and allows for maximum UV saturation which ensure maximum ultra violet performance. Pondmaster products have been designed and manufactured to meet the demanding requirements of pond hobbyists and professionals everywhere. Fish friendly environmentally sound and energy efficient.