This 7.2V Dual Sony L- Series Power System extends your run time on your Sony a7 Camera by using two available Sony NP-F type batteries. This unit comes with a Sony NP-FW50 type dummy battery cable which is compatible with all Sony a7 series cameras. This power system has two regulated 2.5mm jacks that output 7.2Volts. The Plate incorporates a 15mm rod clamp so you can mount it to LWS 15mm support rods. The plate itself features a two-sided design that mounts the batteries one on each face, one battery is required at all times to supply the necessary voltage to power your Sony a7. This unit is hot swappable. The batteries securely snap in to the plate and a release tab must be pressed to release the batteries. A blue LED built into the plate lights up to indicate sufficient voltage to power the unit. This unit is an extremely cost effective power system for those who already own Sony L-Series batteries. Made in USA.