40 Watt Zapper Replacement Bulbs - 2-Pack T8 20 Watt UV Tubes for OUTXPRO 40 Watt Bug Zappers - 15.56 x 1.02 x 1.02 inch (L x W x H) UV Replacement Bulb for OUTXPRO 40 Watt Bug Zappers 4000 hours lifetime per bulb Standard T8 Tube 15.56 x 1.02 x 1.02 inch (L x W x H)