The quartz module is the sleeve assembly supplied as a complete unit rather than as a bare tube — sleeve, seals and end fittings together, ready to fit. This is the 1537 mm module for the WLR30. Note that this catalogue also lists an 1830 mm module covering the VLR30 and WLR30 under item 13214-1114 — measure the module actually fitted, or quote the reactor serial number, before ordering. Wedeco was founded in Herford, Germany in 1976 and is now a Xylem brand.