Ram Mount Flex Adhesive Base with 1-Inch Ball Consists of a 2.5" composite base that connects to a 1" ball, double-sided adhesive PSA stick pad and sealed alcohol prep pad This base will attach to all RAM double socket arms that will accommodate 1" ball bases High Strength Composite A secondary tether is recommended when this mount is used in high vibration environments 1" Rubber Ball "B" Size High Strength Composite This base will attach to all RAM double socket arms that will accommodate 1" ball bases The RAP-B-378U consists of a 2.5" composite base that connects to a 1" ball, double-sided adhesive PSA stick pad and sealed alcohol prep pad Lifetime warranty