The IDX A-DCFX9 V-Mount Battery Adapter for Sony PXW-FX9 is specifically designed for the Sony PXW-FX9 camera. It converts the attached battery to the camera required 19.5V and supplies power via the DC input. By using it in combination with a small battery like the IDX Imicro series, you can build a small and lightweight system that has a sense of unity with the camera.