New Capricorn F18 is 17mm also. I use a rachet wrench stored in a small dry bag in the tramp pocket. hit it with Wd 40 every once in a while and it is fine.

Richard Vilvens
Brand Ambassador
PSA Capricorn USA
R.Vilvens@yahoo.com
Fairfield, Ca
F-18 5150

http://www.capricornsailing.com/