Miter saw laser guides tend to be more sizzle than steak but the Laserkerf II might actually work. The beam illuminates where the blade is actually going to cut and even indicates the kerf’s width correctly. So instead of showing the user a line that’s approximately where the blade is going to cut, this $79 add-on shows exactly where the cut will be made. It’s powered by two AA batteries or by a plug-in cord and mounts to most miters saws. Available now.