The 242103 is a BNC Plug to SMA Jack Straight Adapter with gold-plated phosphor bronze contacts. Body made up of brass with gold-plated finish and PTFE insulator. This adapter is commonly used in applications requiring 2 dissimilar RF interfaces to be connected. Connex between series adapter is used to join two connectors of different series. They are designed to offer the lowest VSWR rating of the two series involved.