The oil level gauge, also known as a dipstick, is usually of the bayonet type (fig. 6-20). It consists of a long rod or blade that extends into the oil pan. It is marked to show the level of oil within the oil pan. Readings are taken by pulling the rod out from its normal place in the crankcase, wiping it clean, replacing it, and again removing and noting the height of the oil on the lower or marked end. This should be done with the engine stopped unless the manufacturer recommends otherwise. It is important that the oil level not drop below the LOW mark or rise above the FULL mark.