High precision oil gauging tape measure. Stainless Steel 30 Meters Product front is made of aluminum, durabl. product design structure can prevent expansion when the blade is pulled out. Product center turntable configuration bidirectional sliding bearing. Reducing frictional resistance when recycling blade. The hook of the plummet bob and the connecting point of the blade can rotate freely and does not get stuck,and the plummet bob digital scale is clear.