Suprachrgd82
GT Fan
It’s a Granite strap mount thingy to carry a toolbag or spare tube. I had some spare stainless button heads to affix to the bottle cage mounts. It hasn’t been used yet…probably should remove it.Excuse me asking, but what attaches to the plate you have on the seat tube bottle bosses?
https://granite-design.com/products/portaledge