This is a well known kit and does produce a very good model, that sails well. The keel/fin has been "thickened" with an additional layer of plywood each side, to increase the stiffness and so an aerofoil section can be formed. The jib works directly off the servo arm, while the mainsheet has a 2:1 system to create enough travel, so the mainsail can go all the way out. The sails are made from some Dacron, rather than the light weight cloth supplied with the kit.