LSE Lighting Compatible UV Bulb for Master Water HIMSV-6 GPH330T5L/4 Wattage: 16W - Bulb Type: Ultraviolet Germicidal UV Base: 4pin (4pins on one end) - Length: 13" (330mm) Glass Type: Quartz Glass Tube Super Life Rating: 12,000hrs This lamp by LSE Lighting is fully compatible with following units: HIMSV-6