SUMO Sacs are made with our own flexible and puncture-resistant fabric, “SUMO Skin.” It has a durable 1000D polyester core that is heat laminated to lightweight plastic film skins with a bonding agent. This sandwich construction is 150% stronger in tearing tests and 37% higher in tensile strength than our competitors, making it the most durable ballast bag available. br Every SUMO sac is double welded to ensure a watertight seal. Our tough SUMO Skin is overlapped and hot air welded. You can see the smooth and clean seams on the outside of every bag, and a second welding operation applies an inch wide sealing tape to the inside of every seam. br Our new SUMO MAX FLOW valve is a new 1½ Inch diameter high flow version of the Sumo LINK system. The SUMO Max Flow valve provides the same hassle free watertight connection to your Sumo Pump but with massive 50% LARGER intake. The Sumo Max system is 100% compatible with the classic Sumo and Big Bag ballast systems. br Our unique LINK system provides a hassle free connection to your Sumo Pump, keeping your boat dry on the inside. The Link Valve is watertight and can also be used as a convenient way to purge air from your bag. br NEW easy turning cap with a perfect water tight seal. Pressure tested up to 6 PSI. Our 1” NPT ports allow built in ballast systems to fill, drain and vent quickly for hassle free operation.