A few years back when the avalanche of special rulers started my sister & I thought we had to have every one of them. Now they have been put away because we really don't need them for most jobs. I do have one set of 4 very special rulers that I bought for $68.00, I used one of them once & when I showed the quilt I had made with it, I was told I did it wrong because my block turned out to be about 10 times larger than it was supposed to. there was nothing else wrong with it, just too big. I never did learn the right way to use the rulers.