I have a 3" Walking Horse Shell Cordovan strop made from Horween shell. I believe Jarrod at The Superior Shave is the exclusive distributor of these. They're hard to get. You never know when he's getting them and when he does, there are usually only a few and go fast. All you can do is check his website regularly.

My Walking Horse horsebutt is my favorite strop and it has a very light draw. I assume the SRD horsebutt strop is comparable, since they're both made from Horween horsehide.

My favorite cowhide strop is the Tony Miller premium steerhide. It has the lightest draw of any cowhide strop I've tried.