20 Watt Zapper Replacement Bulbs - 2-Pack T8 10 Watt UV Tubes for OUTXPRO 20 Watt Bug Zappers - 13.78 x 1.02 x 1.02 inch (L x W x H) UV Replacement Bulb for OUTXPRO and other 20 Watt Bug Zappers 4000 hours lifetime per bulb at least Standard T8 Tube 13.78 x 1.02 x 1.02 inch (L x W x H)