【Length & Packaging】Length: 330 mm / 13.1 inches. Diameter: 25 mm. Sold in packs of 2 lamps. 【Powerful Insect Control】The tube emits a wavelength of 365 Nm, which effectively attracts flies, mosquitoes, and other flying insects. 【Safe and Chemical-Free】Non-toxic, odorless, and chemical-free, and is 100% environmentally friendly and safe for babies and pets. The device is CE and RoHS certified. 【Applicable Model】Applies to most 20W electric fly swatters / mosquito killer lamps / insect killers. Note: Make sure the length and specifications of your previous lamp match ours. How to replace the lamps 1. Turn off and unplug: Turn off the power switch and unplug the insect killer. 2. Discharge: Use a screwdriver with an insulated handle to touch the high-voltage grid for 30 seconds to 1 minute. 3. Screen removed: Remove all screws from the screen and the outer grille on the side where the lamps are located. Squeeze both sides of the outer grille (left and right sides together). 4. Rotate and replace the lamps: Rotate the lamps until the lamp bases meet the grooves in the lamp holders and remove them, replace them with the new ones, then twist a few turns to ensure the new lamps are in place and properly connected to the lamp holders. Light photography and different screens may cause the color of the item in the picture to differ slightly from the real item. The allowed measurement error is +/- 1-3 cm.