Made with chrome plated glass, these 1/4" flow size couplings can really withstand high pressures and are highly durable. They have straight through or internal shut-off valve. the 40CB couplings interconnect easily with 40AC and 40PP couplings. Its operating temperature is Vacuum to 250psi, flow capacity is 1/4" Size and temperature is -40°F to 180°F. the internal valves are made of acetal and the valve springs are of 316 Stainless Steel. The O-rings have qualified DA & NSF Grade Buna-N.