The MIK adapter plate allows you to attach bicycle accessories with a click to the rack and secure them safely. The difference between the MIK key (S and L): The MIK Adapter Plate 2.0 comes with two keys, the MIK key S and MIK key L, for two usage scenarios: MIK key S: The solution for customers who frequently take their accessories with them. By leaving the small key in the adapter plate, attaching and detaching becomes quick and seamless. MIK key L: Ideal for customers who want to keep their accessories securely on the bicycle without constantly removing them. This retractable key is also practical for larger accessories such as crates and baskets, as its length makes it easier to reach the MIK 2.0 adapter plate.