Ultramount JR has the same beefy 3\16" thick steel construction as the standard Ultramount, however, JR is only 7 1/2" tall instead of 9 3/4". Footprint of the mount is 10 1/2" wide by 9" deep.
(Note) With Ultramount JR being only 7 1/2" tall, some press linkages will hang below the benchtop to impede opening of cabinet doors or drawers (If you have them) below your bench. If you have any doubt, before placing an order, measure the linkages hanging down below your bench top and subtract 7 1/2".
If you want to have the press completely on top of the bench, the standard Ultramount will fix you up perfectly.
Top plates sold separately.