Usage Tips:[Fit Models]: T8 10W replacement bulbs compatible with for , for , for , for most 20W electric bug zappers; EPA Est. No. 97341-CHN-1; Please measure and confirm the bulb size of zapper before purchasing [365Nm Wavelength]: Use a wavelength of 365nm ultraviolet light because bugs are particularly attracted to light in that range; This specific wavelength falls within the UV-A spectrum, which is known to be highly attractive to mosquitoes and other flying insects [Long Lasting]: Long lasting bug zapper replacement UV bulbs, more than 3000 hours, in order to achieve the best working effect, it is recommended to replace the T8 10W UV light bulbs in about 3-4 months of continuous use [Bulb Size]: Bulb size: 13L x 1W x 1H inch, total length including pins on both sides is 13.5 inch; Wattage: 10W Color: As Shown Material: glass Package Contents: 4 * Bug Zapper Light Bulbs Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.