I just replaced mine on my ns 27. I replaced the 12mm for 10. Best thing I've done. I found the 12mm was right on the limit with the cars and turning blocks, always got jammed and tangled during tacks, especially in light breeze. With the 10 I found it easier to tack and cleat off as well. I use to clean my sheets on the careel with wool wash. I like the smell.

... Wife wasn't happy when I threw them in the machine on gentle. Bundled up of course.