From your website the band.it looked to be very sturdy and wide. It looked like it had a great grip too. When I got my actual product, it was much thinner than I was expecting and to have it fit such a robust and heavy lens as my Noctilux, it just didn't do the job. It was sliding around and did not give me the grip I was looking for. Very disappointed.
The rubber band is too soft and flimsy. I will have to glue it to the lens to get the function I was looking for, - to clearly separate distans scale and aperture scale without having it falling off.