I have been looking for a 5" x 5" square ruler.....and can't find one. Does anyone have any suggestions as to where to find one??????????????????

I can find 4 1/2 " x 4 1/2" and a 6 " x 6 " inch ruler....but find it strange that I can't find a 5 " x 5" inch ( square ruler .....
If anyone knows where to purchase a 5" x 5" inch ( square ) ruler, please let me know !