Friendlier to Use Bio Vent™ has been specifically designed to seal without caulking during installation. Using an exclusive preinstalled gasket, Bio Vent installs in a fraction of the time needed for other, conventional venting products. All Bio Vent products are constructed with AL29-4C, 26-gauge superferritic stainless steel. Contact: (800) 729-9505 or sales@dalsinmfg.com.