20-piece kit - pack of 10 couplers and 10 plugs so you can have hoses and tools fitted and ready for use 
1/4-inch npt - couplers feature 1/4-inch npt female fittings while the plugs have 1/4-inch npt male threads 
Brass and steel - couplers are constructed entirely of brass while the plugs are rust and corrosion resistant zinc plated steel 
M-style fitting - fits m or milton style plugs and hose fittings 
High flow design - high flow design with wider inner diameter delivers more air and thus more power to tools