Master Electrician RC-021/TR-020 Indoor/Outdoor Digital Timer w/ Remote ControlCountdown function automatically turns power off 2, 4, 6, or 8 hours later, wireless remote control of all functions on transmitter or control manually on the receiver, remote works up to 80' away, weather resistant housing protects connected lighting, transmitter power input, dc 12v alkaline battery, size a23, included, not activated by photocell, can not be used with other electrical timed items products, 8 channel codes for the remote channels "a"