PTPFit Resistance SystemBuild incredible body strength, targeting your biceps, triceps, shoulders, chest, back, core, glutes and legs with the PTP Resistance System. Whether youre new to resistance training or a seasoned athlete, youll find just the right level of challenge with no less than seven resistance combinations to choose from. Secure your door anchor at any height to exert force in any direction and perform over 50 popular gym exercises without relying on gravity.