The cushioning washer that seats a quartz sleeve in Trojan UVLogic reactors, original part number 792931, moulded in EPDM. It measures 1.313 in / 33 mm outside diameter by 1.050 in / 25 mm bore by 0.063 in / 1.6 mm thick. Its job is to keep the sleeve off the metalwork. A quartz sleeve is rigid and brittle, the reactor body expands and contracts around it with water and ambient temperature, and without a compliant seat that differential movement is taken by the glass itself — which is how sleeves crack at the end fitting rather than in the middle. EPDM is used because it holds its elasticity in continuous wet service and resists the ozone and UV present around the lamp. It is a consumable: replace it whenever the sleeve is disturbed, not only when it visibly fails, since a compressed or hardened washer no longer cushions. Supplied by cBallast on quote-to-invoice terms; lead time and freight are quoted per RFQ against the destination Incoterm.