TetherBLOCK is designed to prevent accidental removal of a cable from your camera's data ports, therefore preventing damage to the port and to your camera. By snaking a USB or FireWire, or HDMI cable through the TetherBLOCK's S-channel and attaching the TetherBLOCK to your camera's tripod mount you'll be able to shoot tethered to a computer without fear that a trip over the cable will damage the camera's sensitive data ports. Fits camera's tripod mount via either a 1/4"-20 or 3/8" thread mount.