Work Principle: It works about 30 seconds. After 30 seconds, if you not make voice, the lamp not work. Too bright or in the day, the lamp doesn't work. It only works in dark environment or at night. Trouble Removal: When install it, it will auto light up and off, occasionally it can auto light up, the reason may be there's bulb turns to hot place, or install angle is not correct. Item Name: Sound Sensor Lamp Lamp Holder: E27 Power: 3W/5W/7W/9W/12W (Sound Sensor) Voltage: AC 85-265V Features: Super Bright, Energy Saving, Sound Sensor 3W Size: 84mm x 50mm/3.31" x 1.97" (Approx.) 5W Size: 107mm x 60mm/4.21" x 2.36" (Approx.) 7W Size: 114mm x 68mm/4.49" x 2.68" (Approx.) 9W Size: 128mm x 77mm/5.04" x 3.03" (Approx.) 12W Size: 140mm x 93mm/5.51" x 3.66" (Approx.) Notes: You will find more amazing products if you visit our store. Due to differences in lighting and screen settings, the color of the project may be slightly different from the picture. Due to different manual measurements,allow for slight size differences. Package Includes: 1 x Sound Sensor Lamp