SELKIRK CORP 104081 Universal Male Adapter, 4-Inch Manufactured in china Easy to use Highly durable 4" inch, 4RV-UAM, Universal Male Adapter Designed for type B gas vent Allows Metalbestos B-vent connectors to be used in conjunction with other brands of existing vent Used to adapt to Metalbestos pipe toward termination Features a snap together, non-positional lock system, die-formed ends and eliminates the need for all cutting, fitting and special engineering