Self-supply and dimmable: The non dimmer/dimmer switch requires no batteries and no power connection. The energy is built up kinetically by pressing the switch. Small structure and can be used as non dimmable as well as dimmable. Through long press to circularly dim the brightness to suit any activity. Turn on the light again, and it maintains the last light intensity. With this ENER-J light switch, you don't need to pay the extra money to buy a dimmer. Multiple light switches connectable: A receiver (not included) can be connected with up to 10 switches. This allows you to operate a light source with multiple switches. Quite simply as additional switches to existing light switches. Stepless dimming function and storage brightness. Range and Usage: The effective range between transmitter and receiver (not included in the package) is approximately 30 meters indoors and approximately 160 meters outdoors. ENER-J receiver (not included in the package) can connect to multiple ENER-J switche