Sterilight Quartz Sleeve for these systems:Sterilight Model S5Q-PASterilight Model SSM-24Sterilight Model S5QSterilight Model S5Q-GOLD Hydrosafe Model HSUV-SS-5-1 (made by Sterilight) Quartz Sleeve:All Sterilight UV systems include a quartz sleeve, which surrounds the lamp. The quartz material used in Viqua's quartz sleeves are a 100% fused silica which lend to the sleeve's high transmittance. A high transmittance is important as the UV light must travel through the sleeve to get to the water.There are a variety of quartz sleeve designs, depending on the system that they are being used in. The QS-463 is an open ended quartz sleeve which is used in the Silver series. All replacement sleeves are shipped with two o-rings. qs-463, sterilight, quartz sleeve, uv system, ultraviolet system, s5q, s5q-pa, s5q-gold, ssm-24, hsuv-ss-5-1
