Pinless leg vise (without a criss cross)

I build a pin-less leg vise for my workbench. This design is very simple, and very simple to make. The parallel mechanism is all wood. There is a hardwood parallel guide which runs against a strip of Birch on the under side of the leg rail. Compared to more popular methods like linear bearings, St Peter's cross, or chain-contraptions, this is a winner. It's arguably simpler than building a traditional pin board. I don't know if this idea pre-dates Youtube, but I first saw this method used in Corneel du Toit's video. Please watch his video if you're interested in this design:    • Easy DIY Pinless Leg Vice