Grippers, sometimes called hand grippers, are primarily used for testing and increasing the strength of the hands; this specific form of grip strength has been called crushing grip, which has been defined as meaning the prime movers are the four fingers, rather than the thumb.
There are differences from brand to brand, but the common features of standard grippers are that they use a torsion spring fitted with two handles. The exact dimensions of these elements vary, as well as the materials used to make them; the springs are made from various types of steel, and the handles are generally made from wood, plastic, steel or aluminium.
Stainless steel springFengXun hand grippers use high quality stainless steel spring,durable and long lasting,get rid of snapped springs | Adjusting knobThe hand grippers build with a resistance adjustable knob,Turn the knob clockwise to increase resistance,anticlockwise to decrease resistance. Easy as pie. | Strength rangeRange 10-40kg,increase resistance as your strength develops. Light weight and ergonomic design, exercise anywhere you like! | Rubber covered handleThe handle is covered with TPR,which is relatively soft and won't hurt fingers. |