This UltimateAddons universal handlebar or frame locking strap attachment is designed to fit a wide range of UltimateAddons 3 prong holders and cases. This strap can fit various shaped handlebars or frames with a diameter between 21-40mm, allowing for it to be used on various shapes and surfaces. This attachment will allow you to connect any 3 prong UltimateAddons device holder or case and safely mount your device while riding your vehicle.