Z-Flex 2SVEVWCF04 Z-Vent Stainless Steel Single Wall Vertical Condensation Drain Tee 4". This is the best piece to use as a secondary condensation drain point for all vertical venting installations. This drain tee acts as a 90 degree angle, but it has a reservoir and a drain point to easily remove rainwater and condensation that may come down the exhaust system.