This new heavy bag from Everlast is made from a pateneted new material that is a unique blend of canvas and polyester. This bag provides you with the best of both worlds - it has all the comfort of a polyester bag but adds the tough and uncompromising durability of a traditional canvas bag. this bag also has a specially blended filler that provides maximum shock absorbency. This will help protect your knuckles and bones from the harm of repeated impacts. This bag also has a redesigned nylon and polyester webbing support system. this adds extra strength to the hanaging apparatus to make the bag last longer under extreme conditions. this is an exceptionally durable heavy bag that is also comfortable to use and easy on your hands.