Shimano Post Mount Caliper Adapter for Post Mount Fork Mount is an interchangeable precision engineered disc caliper mount adapter, for post type disc calipers to be mounted to post type forks. Interchangeable, precision engineered Shimano disc brake caliper mount adapters. Designed to mount post type disc calipers to either international standard or post type disc brake mounts on most frames and forks. Available in front or rear versions to suit most rotor sizes & suitable for most brands of post type calipers.