Mariotte Tubes are essential components used with the Double-Ring Infiltrometer to calculate soil water infiltration rates. These tubes serve as a reservoir, maintaining a constant water head during testing while also measuring water volume. The aluminum tube features two valves: one at the base for filling and draining water, and one at the top for venting during refills. Millimeter markings along the tube allow for precise flow rate readings through a sight cut-out, and a sturdy base plate ensures stability during use.