The quartz sleeve separates the ultraviolet lamp from the water while passing UV-C into it. Length, diameter and wall thickness all identify a sleeve, and this catalogue stocks several at similar lengths — order against the reactor model rather than against a measurement of the old part alone. This is the 1000 × 70 mm sleeve for the E5 and E10, supplied complete with its O-ring and wiper. Seals and wiper are included because both are renewed whenever the sleeve is disturbed — a reused seal that has taken a compression set will not re-seat. Wedeco was founded in Herford, Germany in 1976 and is now a Xylem brand.