About the 15w Double-Ended UVC Bulb - BOGOF Manufacturer: UVC Bulbs ADD ONE 15W BULB TO YOUR BASKET AND RECEIVE TWO!!! This quality double-ended UVC light bulb that fits the following systems: FiltersFish Mate Gravity 15/30 UVCsEvolution Aqua Evo 15wLotus 15wTMC 15