I had to special order the extension.
Never used a ruler just meandered.
Lost it & my Lily in our house fire. :(
I replaced it with an Inspira frame. Got the floor model at a quilt show for about the same price that I would have paid for a new HQ. Since the Inspira has legs, DH did not have to build a table for me. I was able to use it out of the box so to speak.