[Fit Models]: 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 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]: Long-lasting UV bulbs with over 3000 hours of lifespan; For optimal performance, replace every 3-4 months under continuous use [Bulb Size]: Bulb dimensions: 13L x 1W x 1H inches; Total length including pins: 13.5 inches; Wattage: 10W Color: As shown Material: Glass Package Contents: 4 x Bug Zapper Light Bulbs Note: The package includes only the items listed above; other products are not included. Lighting and display settings may cause slight color variations between the image and the actual item. Measurement error allowance: +/- 1-3 cm