Straight and Manual Shut-off Valve Set includes: Blue 1/4" x 1/4", Yellow 1/4" x 1/4" and Red 1/4" x 1/4"   . Ball valve design with flexible hose controls refrigerant with a quarter turn of the valve handle. Meets SAE, EPA and UL requirements for containment of refrigerant. Can be operated with one hand. Screws onto charging hose end Mastercool manufactures a complete line of shut-off valves for containment of refrigerant. EPA requires shut-off valves within 12 inches of the charging hose ends to prevent unnecessary venting of refrigerant. Using shut-off valves is much safer than allowing refrigerant to blow out during service.