Shimano SL-6208 Downtube lever boss cover, for SL-R400

This handy-dandy part is for attaching Shimano, and only Shimano, indexed downtubers to your bike. Cannondale made oversized-tube bikes and couldn't use the "normal" (at the time) round downtube washers, so needed a flat one, which is this part. This also happens to be the part you need to put a Shimano downtuber on a Rivendell bar-end pod.

Sold individually, so you'll need two for both sides.