Color/weight guide: Red/Medium: 7lb/finger: The finest exerciser available for the average man"s hand. Black/Heavy: 9lb/finger: For those requiring exceptional grasping power from the finest exerciser available for martial arts, climbing or weapon retention. Grey/Extremely Heavy: 11lb/finger: Our highest resistance exerciser. Appropriate for individuals who already have very strong grip strength but require extreme and extraordinary grasping power. * Red/Medium: 7lb/finger: The finest exerciser available for the average man"s hand. * Black/Heavy: 9lb/finger: For those requiring exceptional grasping power from the finest exerciser available for martial arts, climbing or weapon retention. * Grey/Extremely Heavy: 11lb/finger: Our highest resistance exerciser. Appropriate for individuals who already have very strong grip strength but require extreme and extraordinary grasping power.