These Straplok buttons have a wide collar to keep the strap and instrument securely in place. Replace your standard buttons to get even better Straplok buttons or if you want to use the same shoulder strap with Straplok Retainerready on several instruments. o The most popular Straplok® Retainer System styleo Replace your standard buttons for a better fito Use the same strap with the Straplok Retainer System for multiple instruments. o Available in nickel, black and gold to match most Straplok systems.