These glass-filled nylon hold-down clamps are versatile and economical.
The posts are just shy of 3/4" in diameter, making them usable in most dog holes.
Hold-down capacity is about 3 1/2", less the worktop thickness. The quick-release nut slides freely for fast adjustment, with clamping pressure applied using the red cam lever.
The lever arm is serrated to prevent slipping. The clamps can also be used as dogs or stops and are fully compatible with Workmate. Excellent value.