Ring Writer Clip (Set of 3) (1S 1M 1L) Tens Units Automatic age based target zone : MSHQ 1885 Automatic age based target zone : bpm % * To help you train safely and effectively the training computer determines your heart rate target zone limits automatically according to your age based maximum heart rate (220 minus age) * Weight Capacity is 300 lbs Bag of 3 (1small 1 med 1 Lrg) * Automatically positions and angles the implement correctly for use * Effective for teaching developmental * handwriting skills for grasp development * Provides stability while allowing a more manipulative grip * Offers extra control to overcome gripping difficulties arthritis and limited dexterity * Consists of 2 linked rings * Place finger or thumb in the larger ring and the implement to be used inside the smaller ring 85 cm) Large