BestDealUSA Wireless Remote Shutter Release for Canon 50D 7D 5D Its maximum working distance is up to 30m in open area without blockage. It's very suitable for outdoors use, especially to use for geological prospecting, field shooting, mountaineering travel To control single-frame, continuous-frame and bulb mode, supports 3.5 seconds delay shoot The transmitter has the signal to indicate its current condition: green light is focusing, and red light is shutter or B mode. Same as the transmitter, receiver has a pair of signal status indicator Used the high-quality connection line, the normal length is 30cm, the receiver can be used as a wired remote without the transmitter Has strong anti-interference function and has 16 channels; Energy-saving design allows long battery life usage