I have a Monster Yost vise and it was a great tool. I was looking forward to these pads for some of the pen spins I did. No! Magnets are weak, plastic is very slippery. Maybe he would hold the whistle. everything else wants to slide and dodge. Any deviation pushes the plates off the jaws and your workpiece flies! Remember, this is a giant Yost vise with lots of metal to sit on. My pinky sheds plastic almost effortlessly. Jost makes good vices but clearly bad pads. This movie always pops up in my mind with this brand.