Dorr DC 12V 4CH Receiver is an additional or replacement receiver for the Radio Flash Trigger AC 220V 4CH. Features 4 radio channels with an LED indicator. Requires 2x AAA batteries (not included) and can do around 20,000 trips or one year. For sync speeds up to 1/250s - this depends on the sync speed of your camera. Has a max. radio range of 15m and a delay time of 1/600s.