projects have a maximum jaw opening of around 100mm and a jaw length of 300-450mm, while those used to split flags and natural stone tend to be noticeably bigger, and may incorporate a hydraulic jack to maximise the cutting power on thicker, tougher materials work by adjusting the height of the jaw opening via a screw mechanism so that the block (or other elements) to be cut just fits between the upper and lower blades and then using the eccentric cam attached to the lever to force the upper blade downwards, exerting pressure onto the block and causing it to snap in line with the blades