I've had the Master and Empire (same) and they don't fix very well and the cap on the leveling plug falls off. The cap on this one is really good, doesn't slip when finger tightened and the bottle is sealed with a brass stopper. I really like it when a tool does what it's supposed to do. When I use a 12" Master to line closet doors, the blade slides over me. You need to use pliers to tighten it enough. I work as a remediation company and use the 6" and 12" daily and recommend the Irwin combo. squares.