Armstrong® 11-AV Free Floating Lever Air/Gas Vent, Stainless Steel. The Armstrong® stainless steel free floating lever air vents have been developed to provide positive venting of air/ gases under pressure. The body and cap and all working parts are made of high strength, corrosion resistant stainless steel. Body and caps are welded together to form a permanently sealed, tamperproof unit with no gaskets. Elliptical floats and high leverage provide up to 115 SCFM capacity for these compact air/gas vents. Lever action is guided to assure proper seating of the valve under all operating conditions.