The Bessey Clamping element with fixed throat depth has been designed to suit welding tables with 16mm holes, these have awesome hold down strength, have 200mm of clamping height with a 30-150mm throat.
These are not limited to metalworking though, so for when a decent amount of holding strength is needed, these are the clamps to go to. Woodworking benches traditionally use 19mm or 3/4" dog holes, these are also suitable for these clamps. An adapter is available for 3/4" holes.
The plastic handled clamp gives superior holding strength, with easy access to it. The clamp bar is coated to allow a better sliding action along its length, a bonus in areas that are prone to dirt and dust.