Hoses range from 1 to 4 inches in diameter. Four-inch hoses are used to connect the truck to the fire hydrant. Mid-range hoses are double-jacket hoses that have two layers of cotton over a rubber interior to carry the water. This hose is designed to expand but prevents a high leakage. Some 1-inch hoses are used in brush fires that are one-layered but are lighter. They don’t carry as much water pressure and leak more, but this is a trade-off necessary when dragging hoses up into mountains for brush fires.