The Master Plug can be used with 0.5 in. or 0.75 in. straps or used without straps as a standard plug. Made with a unique two-part molding process, which allows for an extremely comfortable thin stem at the base. The circumference of the Master Plug is 4.8 in. The insertable length is 3 in. Made of TPR with a polypropylene inner core for flexibility and strength.