Big Foot LA-BHMHH Hand Held Bolt Hole Marker Bolt locator, HD bolt locator, ledger bolt locator, plate bolt locator bolt hole marker Five different marks: 1/2" , 5/8", 3/4", 1", and 1 1/4" Ball bearing lock keeps the indicator in place Marks 2x4 or 2x6 plates This is an O.E.M. part