AROMA Hand Exerciser Adjustable Finger Exerciser Mechanical Grip Hand Strengthener for Guitar, Piano or Therapy Exquisite and smooth finger pad design, make finger contact with button more accurate , each finger can get sufficient exercise. Power range 4-7 LB, button can be rotated to adjust power, turn counterclockwise is be heavy, turn clockwise is be light. The independence is strong, finger can be trained separately Use high-grade silicone material, smooth, durable, hand protector is convenient disassembly Small size, convenient to carry