Meike &reg; MK-AR7 Battery Grip With Remote Control For Sony A7 A7r A7s UP to 100M transmission distance FSK 2.4G wireless transmission input frequency, anti-jamming capability brings strong and stable signal Shutter release button, multifunction control buttons and custom buttons, making you feel like shooting horizontally Timer remote function, setting the delay time, exposure time, interval and number of sheets photo All interface block electrodes and signal pins employ pure and thick metal plating technology that provides perfect contact and conductivity, as well as great performance to resist oxidation