Here's a picture I have handy. On the far right is a simple quick attach hand strap (or "wrist strap" or "lanyard ") and on the VP 8x25 as shown is the RYO harness so I can switch quickly back and forth depending on which I want to use. I use the hand strap when carrying bins in the case using the case strap to carry cross body or just carrying the case on a belt if the case includes a belt loop. There are other versions of hand straps available including straps designed for bins, flashlights and cameras. You might have a look at the Optech site for aftermarket straps, cases etc.
In my experience, if you want to carry bins in a case either using the case strap or without the strap on a belt, one reason to do so is to minimize or eliminate other accessories like bin straps and lens covers.
Mike
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