Green Portable Guitar Bass Piano Hand and Finger Exerciser Extend-O-Grip TrainerFeatures:It is easy and convenient to operate.Curvaceous design with ergonomically and compact structure， user friendly.It is very comfortable while practice.Practice without your instrument anywhere anytime， it could be use for strengthen palm， fingers， wrists and other area of hand.The resistance levels could be adjustable， suitable for the auxiliary exercise of instrument playing， physical exercise and other activities.Compact and ultra-light design means you can carry it in your pocket， bag or instrument case.Specifications:Color: GreenResistance adjustable range: 4-7poundsItem size: 8.7 * 7 * 2.3cm (3.4 * 2.8 * 0.9in)Item weight: 71g / 2.5OZPackage size: 14.2 * 10.8 * 3.5cm (5.6 * 4.3 * 1.4in)Package weight: 93g / 3.3ozPackage including:1 * Hand and Finger Exerciser1 * User Manual