Ok, I picked up a Leupold scope that I thought was a Mark 4, but it dosent say mark 4 anywhere. It has a black ring that says Vari-X III 3.5-10x40 Long Range. It has a side focus knob with the Leupold logo. Was this the Mark 4 before the Mark 4 name existed, or is it a lesser quality model? It has a M3 elevation knob and a M2 windage. I shoot USO and dont really know too much about Leupold.