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 735 mm sleeve listed for the Multiray MLR2267. Note that this catalogue also lists a 750 mm sleeve for the MLR 2267 under item 13991-0608 — measure the sleeve actually fitted, or quote the reactor serial number, before ordering. Wedeco was founded in Herford, Germany in 1976 and is now a Xylem brand.