Designed to give access around the jaws for close-in tool work. With a deep recess for holding long spigots and giving rock solid mounting when turning a long way from the headstock without tailstock support. The jaws are also dovetailed both inside and outside on the lip. Three sizes are produced - the size stated is the nominal external dovetail grip. The 50mm jaws are drilled and threaded to accept additional jaw inserts to convert to smaller jaw diameters.