3 type B gas vent female universal adapter from the RV Collection A universal adapter has both a male and female part to allow for exact connection. It is used to connect B vent to/from 1/4 type B Gas Vent. The RV series offers round gas vent pipe and fittings for residential, commercial and industrial applications. It features a snap together, non-positional lock system, die formed ends and eliminates the need for all cutting, fitting and special engineering. It has an improved joint design provides for a rapid and secure connection in seconds. The use of our Lock Tab feature gives installers the option of engaging this tab instead of using sheet metal screws, when required by local code.