Package ListPackage includes 2 sling attachment, they are fit for 20mm rail Easy To Install & Remove Easy to install or remove with the allen key Super Heavy-DutyIt will hold up to years of heavy outdoor use SizeThe size of the adapter is 2.5cm * 5cm, it is fit for 20mm rail, check your rail size before ordering Customer ServiceIf you have any questions or concerns, please feel free to contact us, we will try our best to help you