This is an extra receiver for Canon users who work with the Pixel King Pro Transmitter (please note that this is for the receiver only and that a Pixel King Pro Transmitter is required in order to work with this product). Depending on the model of your DSLR then the King Pro can enable you to shoot at shutter speeds of up to 8000th of a second. It"s operational working distance is a very generous 300 meters. Pixel 3rd Generation Wireless TTL Flash Trigger King Pro. Contents included: King Pro receiver x 1, Manual x 1