Spring-loaded masterpiece
Stainless steel and wood spring loaded thumb isolation trainer made by grip community legend EatChalkGetBig. Comes with three springs that take around 15, 30, and 45 lb of force to compress the thumb pad flush with the handle. Over-tightening can slightly increase the resistance, and under-tightening can slightly decrease the resistance.
Interchangeable springs
Change springs by twisting to unscrew the inner plastic ring from the wood handle. The nut on the other end of the bolt opposite the thumb pad may loosen when unscrewing the inner plastic due to the direction of the threads. If the plastic ring becomes stuck, place in freezer to shrink the plastic. A 12 mm or adjustable wrench can be used to loosen for tighten components. [Instructional video]
Endless ways to train!
You're only limited by your imagination here. You can get especially intense thumb recruitment by hanging the Thumb Trainer between a finger pair.
