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 the lamp for the NLR2581. The matching quartz module for the SLR2581 position is stocked under item 1379-0108. Wedeco was founded in Herford, Germany in 1976 and is now a Xylem brand.