This is a check valve to be used with the PERRY P-22SG (PERG7022) (oscillating pump for GAS AND SMOKE FLUIDS!!) FEATURES: Made of aluminum Allows fluid or pressure to go only one direction through the valve This check valve is necessary between the pump and the muffler to prevent back flow from muffler pressure and residual GAS OR SMOKE fluid from flowing back into the pump. INCLUDES: One Check Valve btm 06/30/94