Most high-pressure hoses are 7/16-inch male and most first stage high-pressure ports are 7/16-inch female, including all the brands we carry. A few brands of first stages use high-pressure ports that are 3/8-inch female, notably very old models from the early days of diving. We offer 3/8-inch to 7/16-inch adapters.

Most low-pressure hoses are 3/8-inch male and most first stage low-pressure ports are 3/8-inch female, including all the brands we carry. A few brands of first stages have a special low-pressure port that is 1/2-inch female, notably some older Apex, Dacor, and Mares models. We offer 1/2-inch to 3/8-inch adapters.