Meister Typhoon Water-Filled Heavy Bag w/Air Core & Neoprene Cover for Boxing & MMAProfessional grade water filled heavy bag with a proprietary tethered air core provides all the benefits of traditional water bags, without the excessive weight Tethered air core keeps the inner air bladder centered inside the bag so every strike hits a consistent layer of water, reducing felt impacts on joints and tendons for more frequent and intense training sessions. Industrial grade raft valves let you customize the bag fill to your desired