Pedro, there used to be a prop guard called the Handler that was manufactured for use on OMC outboards. While I never bought one, I was intrigued by the principle, and molded one in fiberglass. I mounted it on an old Seagull that I had kicking around the shop.I chose the Seagull for it's squared off tips on the prop. The handler came with a 4 blade square tipped prop to replace the buyers existing prop. The primary function of the handler and my copy was to eliminate the vortex formed at the end of each prop tip. The result was a significant increase in thrust and a slight decrease in topend speed. The loss of speed was only noticed on my dinghy
and not my boat.The sides of the guards were not vented as is yous illustration. I have also bought and used similar units from military surplus auctions that were mounted on 25 and 135 hp Johnson outboards. I think this bladeguard would be a great addition to your boat,but I would research as to whether the slots are really beneficial or not.