Power your Sony a7 camera directly from a wall outlet using this AC Power Supply with a Dummy Battery. On one end this handy power supply features an NP-FW50-type dummy battery, which is compatible with the a7, a7S, a7S II, a7R, and a7R II, and on the other end it has a standard US power plug. At the same time it supports worldwide 100-240V power input (using optional plug adapters).
This power supply is very useful for continuous power at an event or in the studio, and the power cable runs 8 ft long so you'll have enough to move around.