Lagute ZYS-2.5LK Touchless Infrared Motion Sensor Automatic Stainless Steel Trash Can Garbage 2.5 Liter/0.26 Gallon Stainless Steel Sensor distance is about 10cm away from the sensor window. The cover will open when you put any object in front of the sensor window. The cover will close antomatically 5-6 seconds later after throwing the rubbish into the bin. 3 AAA-size batteries(not included) last 3-6 months for normal household use. Size: 12 x 23 CM