Bosch 2SVEEWCF0345 3" x 45 Degree Elbow Z Flex Z Vent SS Venting 3" x 45 Degree Elbow Z-Flex Z-Vent stainless steel venting (2SVEEWCF0345) for the Bosch AquaStar 2700ES / Bosch AquaStar 2400ES / Bosch AquaStar 2400E / Bosch AquaStar 250SX / Bosch 635ES tankless water heater. Bosch 2SVEEWCF0345 3" x 45 Degree Elbow Z Flex Z Vent SS Venting Features: • Z-Flex 3" x 45 Degree Elbow • For gas burning category III appliances - rated AL29-4C • For use with Rheem RTG42, Rheem RTG53 , and Bosch 2400E tankless water heaters • Venting for model 2400E • Stainless steel • 3" x 45° elbo