An innovative truss structure creates a very rigid frame without adding a lot of weight. The light weight makes them comfortable and easy to handle, so you can cut with improved accuracy. The unique blade mounting system lets the blade seat firmly at 90 degrees for straight-ahead cutting and also rotates, angling the blade, which provides the frame's back more clearance (useful when sawing the baseline of a dovetail). The amount of blade tension is easily adjusted with a large knurled knob, while a unique cam lets you apply or release blade tension instantly with the simple flip of a lever. The 5" fret saw is the most popular size for removing dovetail waste.