This is the MKI grip, it is designed to hold Games Workshop Model base sizes 25mm, 32mm, 40mm and 50mm by using Shims. It is also designed to grip a standard sized straight sided wine cork in it’s base. It securely clamps together with three sets of nuts and bolts (M3 nuts and M3x12 bolts).
For the latest MKIII version of this grip or all the shims for different kinds of bases go to: www.ebay.co.uk/sch/Garfy
It’s ergonomic size and shape make it comfortable to hold and it weighs next to nothing so it doesn’t add unnecessary strain to your wrist.