From O'Brien cockpit series comes the vibrant and exciting Challenger tube! the Challenger is constructed with a durable 24/26/30-gauge bladder and fully covered with 840/240D nlyon to ensure use season after season. Four webbing handles with knuckle guards protect your hands while riding. Inflatable floor increases comfort. Quick-connect tow hook. Two Lightning valves and 1 Eco Valve for fast inflation. 340-Lb. Weight capacity. 76" x 87". the Lightning Valve is similar to the boston Valve except that it is attached to the towable, so there are no parts to keep up with or lose. The wider opening inflates and deflates 57% faster than the boston Valve. An interior flap prevents air from escaping, even if the cap is not in place. INSIDE diameter of the Valve measures 30mm.