This DC to BLJ31 Dummy Battery Cable allows you to power your cameras from the D-Tap port on V Mount or Gold Mount Batteries. When relaxed, the cable is 20" long and can be easily managed, and it stretches to 36" long when you need the additional length. It supports an input voltage range of 12 to 17V, and it outputs a power-regulated 8V. The power regulator is neatly tucked away in the dummy battery, so it doesn't interfere with the cable.