R744 - Mastercool - CO2 - 2-WAY PISTON VALVE MANIFOLD FOR CO2 (R744)Mastercool 2 WAY PISTON VALVE MANIFOLD FOR CO2 (R744) 55661 A Mastercool 2 piston valve manifold made for CO2. 1 4 SAE steel braided hoses to handle the extreme pressure of CO2 systems. Oil filled gauges to stop gauge fluctuation and maintain accuracy when monitoring. Features: Free floating piston valve results in less wear and tear in comparison to market standard twisting piston valves O ring with back up o ring allows for a better seal at high