2 Danuser 3-point hydraulically driven post drivers. Have modified both to be Cat 1 size (has been 0, could be returned to that). These are drop-hammer style drivers, the hydraulic motor basically drives a rubber wheel while your raise/drop lever engage that wheel into the pile driver body, so you can short-stroke it or do a full drop. We primarily did 6” or smaller, there was some room so it ‘could’ do larger, but I wouldn’t get too much bigger.
One is a model MDH-1, a solid frame body, hoses are good, the drive wheel still has good life left. Other is a BMD-H, which has a pivot between the 3-point connection and the driver body (basically works like an auto-tilt to ensure the driver body is plumb to the ground (at least in the side-to-side axis). Hoses have some weather cracking and the drive wheel is a little more worn. I have a manual for the MDH, but the general operation and adjust appear to be the same for both, just a difference in the 3-point frame style. Both have the leg kits for storage (although we always kept them strapped to a tree as well for additional safety when storing longer term).