Boston valve- T are two bladders with boston valve. Quicker to inflate and deflate than other valves. It can be inflated by mostly electrical pump with any power. One for the bottom pillow is on the back and the one is on the front. When filling you just take the top cap off so that all the air doesn't come out on you.Please note that make sure the plugs are in tight after inflated. Bigger size- Quick large boating tube makes it great for 2 good sized people to sit on at once. Please note that the max weight of riders is 340lbs. Extra high backrest and sidewalls increase the ability of stable and fun. Dual tow points- Allow for 3 completely different riding experiences. Connect to the quick attachment in front for seated with thicker EVA padding, or towing it backward for kneeling like chariot style. Or just anchored it in the shallow water like a floating couch. Easy to switch from front to rear adds a new dimension of excitement on the water. Comfortable and stable- Very stable and safe at moderate speeds for younger kids. This ski tube is a nice compromise between comfort and stability. Giving the riders a rough and exciting ride but t was never any fear by younger riders that it would tip over. Many handholds are placed perfectly and it travels well across the top of the water. This item is in the category "Sporting Goods\Water Sports\Wakeboarding & Waterskiing\Tubing & Towables". The seller is "elvak-24" and is located in this country: US. This item can be shipped to United States.