S length. Sure you would like some force, but this is due to the fact that the short adjust buckle is held in place by friction. This might be the weak point to anyone but I have found this to get of no issues for me, the sling hasn't missed https://johnnyarnbp.blogofoto.com/65875095/the-greatest-guide-to-barska-compact-biometric-safe-with-biometric-access