The little twister templates come in two sizes, small for 5" blocks, large for 10" blocks. Great for charms and layer cakes sizes. There is a book with patterns to show you how to use it. I'm one of those who do better when I see it do a local quilt shop demonstrated it. There is a lady on here who had a Christmas Wreath wall hanging for her avatar that used the smaller twister ruler.
Great way to get rid of scraps. You can probably find it at any quilt shop or on ebay. Try to google 'lil twister'
template.