Features:

--Easy to use.

--Mechanical design, no power required.

--The compact design can be carried around, whether in the office, gym, or at home, it can be used as a toy to relieve stress at any time, and can also exercise arm muscles.

--Exercise your wrists and hands.

--The hand booster ball is a centrifugal force generated by the interaction between wrist rotation and internal rotation core, which can maintain the high-speed rotation of the core, promote blood circulation, increase the strength of fingers, wrists, hands, forearms, biceps, triceps, ligaments, and shoulders, and restore muscle strength.

--Automatically start the design.

--The operation is very simple, just push the iron core in the direction of the arrow, activated by the internal spring. Please wear a dedicated wristband during exercise to ensure that the wristband will not be lost due to excessive force.

--Durable and sturdy.

--The ball core is made of zinc alloy material and has no strange vibrations.