Had my frame re-finished, and now I can't stand to put the old parts back on. Have replaced most everything, and am down to the above piece. The bolt head has a small protrusion that fits into a small slot in one of the ears, thus allowing the nut to turn without holding the bolt head with a wrench. It would appear that these come in at least a couple of different sizes. I've measured the outside dimension (outside of ear to outside of ear) and that comes up as 23mm. Did I get the right measurement? Good source for these? (cheap shipped).