New charging hose adapter. Converts your R12 or R22 a/c gauge set to R410a use. It converts 1/4" hoses to 5/16" hoses. You need at least one to charge your R410a system or two to get a true vacuum pull and a/c system reading. You can leave the center charging hose 1/4" for an R12 or R22 vacuum pump. If your refrigerant bottle has the 5/16" fitting, you will need three adapters total.

1/4" on the left and 5/16" on the right in the pic.

These fittings have nothing to do with automotive use.

90 day warranty. Free USA shipping.