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. Check the pin count on the existing lamp before ordering: this catalogue lists otherwise identically-named lamps in both 2-pin and 4-pin bases, and they are not interchangeable. This is the 4-pin lamp for the SLR 25143. The 2-pin lamp for the SLR 25143 V is stocked separately under item 1305-0104. Wedeco was founded in Herford, Germany in 1976 and is now a Xylem brand.