The rulers come in two sizes, the small size can be used with a charm pack or would also work well with a 2 1/2" jelly roll strip. The second is larger and works with your 10" layer cake squares.
I used the small ruler with a charm pack and made a couple of throw pillows for my sister for her couch. I originally made the pillow for a demonstration I did in my shop. I used Road 15 by Sweetwater for Moda. My sister saw it and "had to have it" so I made another one and she now has two! The ruler makes your cutting so easy, and it took me longer to actually arrange the placement of the half hexies than it did to sew them together. They sew together perfectly, the seams matched, they looked nice, it was easy to press -- and I can't say enough good things about it. I loved that there were no "Y" seams to try and sew like with the traditional hexie. You can still achieve that old fashioned pieced look and it's so much easier!!
Here is a photo of the block before it's quilted so you can see what it actually looks like before it was a finished project. I used a 20" pillow insert and made the top a little larger. In the photo I placed 7 half hexies horizontally and built my rows so they were 11 half hexies high.
I quilted it up, made my back, trimmed the top to fit the back by squaring up the edges -- and had a darling pillow in no time.
This picture did not upload well -- or my eyesight is getting worse!!
The web is a wonderful source for ideas and I found a few of these images to share, they are not my original photos or work.
This is a good example of the larger half hexie made from Scrumptious by Bonnie and Camille
This is also a larger half hexie which shows them sewn together into the quilt top
This fabric is Odds and Ends by Cosmo Cricket