Shape and strengthen your neck like never before, anytime, anywhere! These products are designed to be used with a lifeline resistance cable and door attachment (not included). Tuf Nex economy model doesn't come with chin strap.This device is totally portable, quiet, and extremely user friendly. It will safely and effective strengthen your neck in the home or in the office. Great for use in concentric/eccentric contraction or a progressive variable resistance training program. Includes instructions with suggested strengthening and rehabilitation exercises.