OK....This is what it says on the ruler:
24" Ruler with Adjustable Locking Fabric guide QR-WSCR24
Quilter's Rule www.quiltersrule.com 800-343-8671
It is made by Westalee design in Victoria, Australia
I bought it at the Houston Show.....(I think???) this last year.
Hope this helps!
They do not give you a screw driver with this and the chanel on the screw is quite wide....so you must find a screwdriver that does not destroy these screws!