CZ21 with 10.5 here. I have no problem with it. I did however coat my coil with marine epoxy so i don't have to use a coil cover. The epoxy is a light gray color and it makes it easy to spot under the water. As opsed to the all black coil.
It has held up all year. No more falsing do to a cover full of sand. And you can see the coil in the water. It's thicker than bed liner. If any ware spots show up i just fill it in. I'm very anal retentive about my equipment. It took me a long time to try it. Im glad i did.