M-D Building Products 92346 SmartTool Module only Have tasks where you really can't see the SmartTool but need instant feedback? Then turn on the audio beeper. When turned on with a single button, SmartTool lets you hear when your task is at level or plumb. This can be great when shimming projects, leveling buildings, pool tables or other projects where you need immediate feedback but are not in a position to see the display. This can leave your hands free to adjust, nail, or screw the project in place when you hear the beep telling you it is where you want it. Hold The hold button makes it easy to measure in areas where the digital display is not visible. Take the measurement, push the hold button, and then bring the SmartTool in front of you to see your reading. Technical Details - Angle accuracy to 1/10 of a degree - The mode button lets you see angles in 3 ways: degrees, % slope or pitch - Audible tone allows for hands-free operation - Runs off of a standard 9v battery - Automatic shut-off after 5 minutes http://www.besttoolsforyou.com/Buy-M_D_Building_Products_92346_SmartTool_Module_only-B0000225AL.html