EGOJIN Weight Training A System Built High-Elasticity Spring Adjustable Chest Exerciser / Safety pin Expander Muscle Hand Gripper Fitness Features - Inside Spring of compression way. (Protect From Springs.) / Strength fine adjustment lever. / Non-Slip Grip (for User Convenience) / Safekeeping with safety clip(Easy storage, Injury prevention) , Power adjustment rod is adjustable to strength (9.6kg ~ 21kg) Material - Plating Iron Plate, Springs (Steel Wire) / Size - 500 x 125(mm) / Weight - 1.5KG Was design for injury prevention from spring in chset exerciser. Beginners also can use because it allows fine adjustment. Non-Slip grip reduces the discomfort during exercise. You can Also adjustable the width. Please strengthen muscles safely. Priority is safety. ( JJS Shop Worldwide Warranty )