On my Maricopa Shop Hop here 2 weeks ago one of the shops had it and they were doing a demo with it. It is a regular ruler with a 'diamond' edge on it that helps to keep your blades sharp. The person that was doing the demo said that he had a blade with a nick in it one day while doing the demo and after a few passes the nick wasn't there any more. He also stated that it would be great with a new blade to keep it sharp more than taking all of our old dull blades and sharpening them. Oh, and he was using an Olfa cutter and blade. The ruler itself is frosted and they run about $20.00. Here in the valley the shop is 3 Dudes Quilting in Chandler area. 5053 W Elliot Rd, Phoenix is the address if anyone is interested. I was not interested due to price and I don't really care for frosted rulers.