Need help on dimension of the collar of the ebrake

[Sparktree]

I ordered custom ebrake leather boots from redlinegoods awhile ago, but they need to know the dimension of the collar of the ebrake, which I am guessing is the diameter or the perimeter of the handle area. I shaved my current ones to fit a custom cover so they also need a origininal standard demension of the e-brake (handle) area. Can anybody help me out? There is no problem in making my boots because I phyically sent in my ebrake rubber covering, but they need to know the original size so the boots will be available to everyone else. Thanks in advance.