Features: It can help increase hand strength, improve grip strength, and improve finger flexibility. Made from silicone material, rings designs increases friction, non-slip and durable. 3 different strength can be adjusted, suitable for each training stage. Small and portable, you can exercise hand muscles at any times. Suitable for people who need to strengthen their hands, such as athlete, Musical Instruments, office worker, etc. Can be used at home, office, gym and other places, convenient and fast, at any times to carry out hand strength training. Specifications: Material: Silicone Color: Pink/blue/light blue/gray/black Size: Approx. 7.8x7.8cm/3.07x3.07inch Pink grip strength: 20-30-40LB Blue grips strength: 30-40-50LB Light blue grips strength: 40-50-60LB Gray grip strength: 50-60-70LB Black grip strength: 60-70-80LB Note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Hand Strengthener Grip Rings