Usage Tips: T8 10W replacement bulbs compatible with most 20W electric bug zappers; EPA Est. No. 97341-CHN-1; Please measure and confirm the bulb size of your zapper before purchasing 365nm Wavelength: Emits 365nm ultraviolet light, which is highly attractive to mosquitoes and other flying insects; This wavelength falls within the UV-A spectrum Long Lasting: UV bulbs last over 3000 hours; For optimal performance, replace every 3 to 4 months with continuous use Bulb Size: 13L x 1W x 1H inches; Total length including pins is 13.5 inches; 10W power rating Color: As shown Material: Glass Package Contents: 4 x Bug Zapper Light Bulbs Note: Light reflection and display differences may cause slight color variation between image and actual item; Measurement tolerance is +/- 1-3cm Only the items listed are included; additional accessories not shown are not included