Anderson waterproof sleeves. Used to help protect the rear end of the jack plugs, where the cable enters the connector. Helps protect against dust, dirt and water ingress and the inherrant risk of corrosion of the electrical connecting surfaces. These PVC moulded sleeves offer dust and moisture protection helping to prevent corrosion and damage. There are two sizes available, one for the smaller 50 amp connector and the other to fit the standard 175 amp connector. They also provide some supportive strain relief for the actual cables.