To mount the mirror, pull the top of the rubber hood off the STI lever clip, slip the mirror base over the lever clip, and place the rubber hood back onto the clip we've cleverly integrated into the mirror base. When mounted on the lever, the Mirrycle Road Mirror is located in the very position for viewing to the rear. Just a flick of your eyes allows for a quick view behind. The Mirrycle Road Mirror can be attached to either the left or right side lever. All necessary tools are included.