Length & PackageLength: 330 mm / 13.1 Inches. Diameter: 25mm. Sold in sets of 2 bulbs. Powerful Insect ControlThe tube emits a wavelength of 365 Nm, which effectively attract flies, mosquitoes and other flying insects. Safe & Chemical FreeNon-toxic, odorless and chemical free, and is 100% eco-friendly and safe for babies and pets. The device is CE and RoHS certified. Applicable ModelApplicable to most of 20W electric fly killer / mosquito repellent lamp / insect killer. Note: Please make sure the length and specification of your previous lamp matches ours. Assured after-sales serviceHigh quality fraxinus tube, guaranteed for 12 months. Fraxinus is a quality manufacturer specializing in electric fly killers and lighting equipment. We are committed to providing customers with safe and reliable products and excellent after-sales service. How to replace the bulbs? 1. Turn off and unplug: Turn off the power button and unplug the bug zapper. 2. Discharge: Use a screwdriver with an insulated handle to touch the inner high-voltage grille for 30 seconds to 1 minute. 3.The display removed: Remove all screws from the display and the outer grille on the side where the bulbs are. Press both sides of the outer grille (left side and right side together). 4. Rotate and Replace Bulbs: Rotate the bulbs until the base of the bulbs meet the slots in the bulb holders and pull them out, replace them with the new ones, then twist a few turns to make sure the new bulbs are in place and connect with the bulb holders tightly. Light shooting and different displays may cause the color of the item in the photo a little different from the real thing. The measurement allowed error is +/- 1-3cm