patented extendable finger exerciser,a great practicing aid for beginner guitarists and pianists extendable finger exerciser is a perfect tool for beginner guitarists and pianists, helping to build up strength and reach with your ring and little players:strength and flexbilliy is very important especially when playing challenging solo pleces where a high skill level is required and the is used a lot. for beginners:playing barre chords can be a tough challenge and the exerciser helps you overome the problem easily. tension range: 2.5lbs-6lbs. help the neglected reveresd finger practice( the finger lifting speed practice),which is often neglected the during the early of tecching,and to assit skill development. beginner guitarists and other instrumenta players. Color:Black Brand Name: Model Number:-10P Type:Finger Exerciser Material:Plastic Package Contents: 1* Finger Trainer Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.