Paul Components Shimano thumbies shifter mounts, slvr pair Thumbies have a hinged clamp for an easy installation They have a shifter mounting boss that fits Shimano bar end shifters and most Shimano downtube shifters Machined in the USA of 6061 aluminum Includes right and left mounts to convert bar-end shifters Paul Components Thumbies convert Shimano bar-end shifters into flat-bar shifters with these mounts.