MOSISO 56 inch Shoulder Strap, Adjustable Thick Soft Universal Replacement Non-Slip Fit Padded with Metal Swivel Hooks for Laptop Shoulder Bag/Laptop Messenger Bag/Crossbody Bag, Black

I use this, and I think I upgraded the straps. It works great for any regular sized body, like the R7, and a 100-500. When I find the straps I'll link them. Here's the straps I use. They hold their place 100%, which is more than I can say for many straps I've tried, and they have swivel ends which are very helpful. I also use these straps on much bigger setups, they're the best.