There are companies in the water industry that are selling "knockoff" lamps targeting residential UV systems that are sold world wide. These lamps are being offered at a very low price with the promise that they operate the same as the UV manufacturer's lamps. This promise is untrue. If a consumer were to install a "knock-off" lamp the "water confidence" that was being offered by the UV manufacturer no longer holds true and cannot be supported by the manufacturer and void the warranty on Trojan® & Sterilight® systems. H2O provides only original Trojan® & Sterilight® Replacement Lamps.