Ironmind is a company which sells many strength building tools for old fashioned
strongman training. They sell
kettlebell handles,
thick handled
barbells and
dumbells, and a whole section of tools for developing grip strength. The flagship item of these grip tools is
Ironmind's line of Captains of Crush Grippers.
Like the typical gripper you might have once used or still use, the grippers are held in the hand and squeezed. The gripper has two cylindrical handles, 3/4" thick and 3-3/4" long, joined by a double coiled steel spring, making a v-shape. The grippers are held with the spring part up.
C.o.C. Grippers come in five strengths. The trainer is 100 lbs, the no. 1 is 140 lbs, the no. 2 is 195 lbs, the no.3 is 280 lbs, and the number four is three hundred and sixty five pounds. The grippers are identified with a number (or a t if it's the trainer) on the bottom of each handle.
When a person can close the number three gripper under authenticated conditions, their name is placed in the Ironmind catalogue. Only five people to date have closed the number four, Joe Kinney, Nathan Holle, Tommy Heslep, Magnus Samuelsson, and David Morton.