Features: 1. The wireless switch has a built-in micro energy generator.  2. Pressing the switch, generates enough kinetic energy to create and transmit a radio signal and switch on/off via a receiver (wireless controller) the lamp.  3. Solves the problem of having to install switch wiring from light fitting to the wall switch. 4. Fast and easy installation in any location, install on any surface such as glass, marble, wood and metal and does not require a back box to install.  5. No batteries required. Very convenient.  Specification: Condition: Material: ABS Color: As Pictures Shown Installation Aperture: 60mm Rated Current: 16A Rated Voltage: 250V Type: Three Gang Switch, Four Gang Switch(optional) Three Gang Size: approx. 9.3* 8.7* 3.4cm/ 3.7* 3.4* 1.3in Four Gang Size: approx. 14.5* 8.6* 3.4cm/ 5.7* 3.4* 1.3in Weight: Approx.50g~196g/ 1.8oz~ 6.9oz     Package list:  1 * Switch 2 * Screws Note: 1. Please allow 0~1 inch error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.