A UV lamp is a scheduled replacement, not a failure item. Its UV-C output falls steadily through life while the lamp continues to light normally, so a reactor with visibly working lamps can be well below its dosing duty. Replace on elapsed operating hours against the measured intensity trend, not on the lamp going out, and handle the new lamp by its ends only. This is a replacement lamp for the Multiray MLR 25840. Note that this catalogue lists a second MLR 25840 lamp under item 13323-1118 at a different price; quote the item number when ordering. Wedeco was founded in Herford, Germany in 1976 and is now a Xylem brand.