Milton 1251 2 Deluxe Compression Tester Replacement Valve Core (Box of 5) PMV grease pump which ensures a high degree 1.75 Inch Cutter Planer which ensures a high degree of suction and makes it suitable for the transfer of non corrosive lubricating oils or viscous liquids It quickly pinpoints external leaks This is a special valve core replacement piece is used to measure engine cylinder compression when combined with the Milton® compression testing gage #S 1251 Deluxe Compression Tester Replacement Valve Core (Box of 5)Replacement part for Deluxe Compression Tester #S 1251Not for use with standard valve coreMaximum of 300 pounds per square inch