Captains of Crush Grippers: designed and built for performance. Known around the world as the gold standard for building and testing hand strength, Captains of Crush Grippers are the single most important grip strength tool you can choose--for the fastest route to the strongest grip. Knurled aircraft-grade aluminum handles, pioneered by CoC Grippers in 1995. Proprietary GR8 springs, only on CoC Grippers: accurate, precise, durable. A 20-year history of product development and refinement. Precision manufacturing for gold standard performance, feel and appearance. Made in the USA. No-surprise geometry: you can count on the consistency and precision of Captains of Crush Grippers. Captains of Crush Grippers: Maximum grip strength, minimum time. No. 1: Where serious grip training begins; most people who lift weights can't close it at first. You'll want to master this gripper if your job or favorite sport or hobby involves grip strength.