The Jessem Rout-R-Lift-II has separate models for different router motor diameters. They are not interchangeable.
The Jessem Mast-R-Lift-II has adjustable blocks that securely hold a wide range of router motors.
The Incra Mast-R-Lift-II (made by Jessem) is different (besides color) only in that it has steel throat plates that are held in place by strong magnets, and do not require tools to remove/replace. The Jessem version has plastic inserts that require a special pin spanner wrench to remove/replace. The tool is included.
I have the Incra, and the manufacturing/design quality is excellent.
-- Andy - Arlington TX