The Strip Tube Ruler by Cozy Quilts Designs
The Strip Tube Ruler You asked for it, and here it is This ruler makes half square triangles a breeze by combining brilliant engineering with "the tube technique." It's perfect to use with strips and even includes directions to make the favorite block from 2" strips: The Daniela Block. With this great gadget, you can easily make accurate half square triangles from 1" to 9"