The A-Line-It Smart Bar system is used to check the accuracy of an existing alignment between the edges of the miter box and the channel for the saw blade. The smart bar is a spring-loaded measuring tool. To use it, you put one end against the blade and release the springs, which lets the bar expand until it reaches one of the other guides on the saw, if the saw is out of alignment. This is part of both the basic and deluxe packages of A-Line-It tools.
The dial and ratchet tool is used for measuring exact alignments (where the smart bar checks for how true an offset is, this measures distances between parts of your saw). The ratchet indicator measures to a precision of 0.001 inches. This is part of both the basic and deluxe packages of A-Line-It tools.
This tool is used to measure the depth of the mitering groove on a saw. On the basic tool kit, this item is 3/4 inch by 3/4 inch by 5 1/2 inches; the deluxe model has one that's twice as long (3/4 inch by 3/4 inch by 11 inches). In addition to the miter groove depth indicator, the deluxe kit has a guide bar for drill presses and routers. Both of these have finely tuned spring assembly systems to make them auto adjusting when used to check alignments.
When using the A-Line-It system, the tools are used in concert – the smart bar is used to measure the angles across the entire table saw, and the miter groove depth indicator is adjusted with the dial and ratchet indicator to measure how close the tolerances are. Once the measurements are known, small adjustments can be made on the saw to move the blade or the miter box into the desired alignment. Both kits come with an instructional DVD that walks you through the use of the tools.