Featuring an NP-FZ100 dummy battery, the D-Tap to Sony a9 / a7R III Dummy Battery Power Cable from Wooden Camera allows you to power the Sony a9 or a7R III from D-Tap power sources, particularly brick batteries with a D-Tap port. A voltage converter box integrated into the cable converts 14.4V to standard 7.4V required by the camera. Additionally, reverse polarity protection is built-in to protect against damage if the cable is plugged in backward to a D-Tap.