The Video DC Block isolates the DC offset from a video source to an Extron product, preventing video distortion. Video DC blocks are installed by twisting them onto the RGB inputs of Extron products. Cables are then attached to the Video DC Blocks. The horizontal (H) and vertical (V)channels do not require them. The small shape of the adapter ensures that the back panel of an Extron Matrix is neat even when many Video DC Blocks are attached.