This is one of the most expensive single items I've bought for my mill, but it was absolutely worth it. This and the tool touch off have saved me hours of time in getting my tools and work-piece setup. The one tool does x,y, and z registration, and you don't have to worry about forgetting to compensate for the offset from a regular edge finder (which used to stress me out). Now I can quickly dial my tool heights in without the need for a paper shim and the height setting is always perfect. In retrospect I should have gotten the one that comes attached to a CAT 40 tool holder because I have a collet tool holder dedicated to just this anyway, but I am very happy.