0-20 Pullups Back Trainer

◎ Join the millions completing the Zen Challenge Series! ◎ 0 to 20 Pull-ups in 6 weeks! ◎ Featured on Glamour Magazine, Yahoo! 's Appolicious, Popsugar Fitness, Apple's "What's Hot", Apple's "New & Noteworthy", and doctor recommended on healthTap! Are you ready for the 20 Pull-Ups Challenge?