Where can I get some graduated(marked) ring straps?

Hi,

I would like to have my rings with a graduated strap. Meaning with marks at 1ft, 2ft, 3ft, etc.  Does anyone know where to get them? or how to mark them maybe?

These can be picked up at many sports stores, at least in Australia. On my own set I have marked the lengths i set them at the places I train most commonly, rather than numerate the length per se, which I find more useful