there was a discussion on the board just a couple of days ago. search & you can read the comments. personally, as a quilter who has worn out a lot of rulers, I think they are something that would just be a bother to use. get yourself a good 6 1/2x12 & 6 1/2x24 ruler set. learn to use them together & you can solve almost any situation. I like to have 2 of the 12" rulers. an 18" comes in handy too. for the money you spend on this "addition", you could just buy another ruler. I have wasted a lot of money on gadgets thru the years--always go back to the tried, true, easy.