The StrongerGrip Strangler, a large diameter 4.5" cylinder with quick attach carabiners and chain for various open hand grip exercises. My first thought was two hands gripping someones neck, then lifting. It's a fun movement, challenging and also works a lot of different areas, core, open hand grip, crushing pectoral power, shoulders, and the heavier you go, your going to engage every muscle in your body, from the ground up.
It's also great for cupping, overhand, holds, pulls on bar or pulley machine. Over hand grip, like a blob but tougher. Underhand thumbless pulls, holds. Great simple tool for adding some spice to your grip work.