This hand exerciser is a spring based device that works by gripping the exerciser and pulling the spring attached bar towards the gripped bar. These are moderate stiffness springs so is convenient for most people to compress fully. The aim is to do as many reps as is conveniently possible at a time and increase gradually. This is also a handy exerciser for recovery from hand stiffness, especially due to injury or weakness. As it works on the extremities, it is beneficial for circulation and nerve strengthening and sensitivity. Also, a suitable rehab aid to increase the mobility and strength of the knuckle joints.