Pneuflex's model of SPGJ 5/16-1/4 is 5/16" x 1/4" plug-in reducer - stainless steel pneumatic push-in fittings, used to connect tubing of reducer and be pushed into another pneumatic fittings. Composed of 316 stainless steel body and 301 SS collet & FKM (Viton) seal, stainless steel plug-in reducer push to connect fittings can withstand harsh, corrosive environment and can transfer air, water, oil, weak corrosive fluids, great for used in water treatment plants, food & beverage, medical and pharmaceutical industries.