[NOONCRAZY ARM TRAINER] Twister arm trainer regarded as powerful assistants for upper body muscle training. Whether it's the biceps, triceps, deltoids, pectoralis major, or even leg muscles, etc, they can all receive effective stimulation and exercise, helping you shape a solid, strong, and well-defined upper body. [CHEST EXERCISER FOR MEN] Our twister arm trainer for men & women has a unique two-stage adjustment function and is equipped with 2 sets (4 spring workout bars) with different resistance, which can form 30/60/90/120 pound four stage resistance exercise. Easily meet your diverse exercise needs. From basic warm-up, rehabilitation therapy to advanced muscle shaping, our twister arm exercise set that meets all your needs.