Here is an image of the end cap located on the enclosure tube. There are a total of 8 holes fitted with penetrators purchased from BlueRobotics. Six of the holes will have the thruster cables fed through to the motor drivers. The remaining two holes will house the power cables from the LED lights, and camera and additionally the coaxial cable. The main tether is fed through a water-tight flange that feeds the main power lines, Ethernet, and video cable between the onshore station and on-board electronics. The red plug is a nifty tool that attaches to the end cap and allows the release of pressure within the tube simply by rotating its back cap.