Keeping your regulator protected from the elements when it is not connected to a cylinder is important to your safety and the reliability of your Life Support System. Protect your regulator from water, dirt, dust and crawling critters. This non-corrosive Rubber Yoke Style Protector Cap is the best kind to ensure proper protection. It seals over the first-stage air inlet when you snug down the yoke screw of the regulator in place to protect your regulator from having water enter inside the delicate internal mechanism when washing your gear after diving. Cap also protects humidity from entering your regulator when stowed for long periods of time. Cap comes with a loop of line to attach to regulator yoke, so its right there when you need it.