Wolfx Un-filled 4ft Punch Bag is made from High Quality Synthetic leather which has an Extra Ordinary Strength and life. The Punch Bag is carefully Stitched and Checked for every Detail before it is Filled to the Highest Standard. The Design Features a Zipped top which can be Opened/Closed to Increase or Decrease the Amount of Filling. Punch Bag comes with a Free Swivel Chain for Hanging Essential Training Aid for Keeping Fit, Exercise, Boxing, MMA Kickboxing, Karate, and other Martial Arts 18 inch long Wall Standard Bracket to hold Heavy Punch Bags up to 50kg. After Filling we use to check the Strength by using each Bag with different means. Tethered loop Facility at the base of the Punch Bag ensures Swing Reduction