I have made a couple of single barrel clamps using electrical conduit clamps etc. The green one is a pipe clamp half with a ratcheting strap off a snowshoe. These are taking up room in my junk drawer. PM me your diameter and if interested you can have either or both if you pay shipping. View attachment 65979
I use the bino hand for my 8x30 porro prisims as well as my big 15x63 Optolyth bins. Everything is totally secure, at the cost of some weight and a closure that isn't as rapid as others.