The set of two red Head jack covers will stay together with strong nylon line keeping them secured. The idea is to run the nylon line and one of the red covers through the front of a Power Pack's shoulder strap D-ring. Then regardless if you are using one or both of your Head jacks the red covers will stay there and be ready when you are ready to pack your gear up when completed with your shoot.
These are the same covers originally provided with Classic Packs individually and now already attached to the modern Packs. This is for replacements for lost covers. Individual covers without leashes are called the ACCP.
These DO NOT help make the Lumedynes water proof! They do help avoid splashes reaching your high voltage connectors. Don't get Lumedyne gear wet. However, these should help keep your important connectors as clean as possible whenever they are not in use.