I just used Ronstan size small on my heliums with 7mm cord, so far so good but they are definitely not time tested.
I bought some off of amazon and I’m not that enthused. Here are some cons. They are huge and make it hard to stack helium’s nicely. They are not very high quality. I had to drill a hole at a slight angle to get the mounting bolt to line up. They make a loud metal banging together noise when you remove your rope. I tried tape to quiet them down but it didn’t last very long. Pro’s are they are unbelievably easy to get on and off the tree and get very tight to the tree with not effort. I just don’t trust them over 3’ off the ground even though I literally jumped up and down on them trying to get them to fail and they seem fine. I weight 225 and they seemed solid. That being said, I’m going to a small versa button with the versa straps. Just my experience.Lots of other brands out there on Amazon and eBay. Anyone have any luck with those? Does anyone have a good way to test these for our uses? I'll purchase a few and have them sent directly to anyone that wants to tackle this.