This Heavy-Duty manual coupler works with 1/4" Body Industrial Interchange Plugs/Nipples. If your job depends on air don't risk leaks and downtime over a few bucks. Buy professional grade fittings. No leaks. No downtime. Your tools will thank you! This listing includes 1pc 3003 1/4" Coupler Body x 1/4" Female NPT, 1pc 3103 1/4" Coupler Body x 1/4" Male NPT, 3pc 10-3 1/4" Plug Body x 1/4" Male NPT, 2pc 11-3 1/4" Plug Body x 1/4" Female NPT.