Carat (mass) Despite its being a non-metric unit, a number of metric countries have used this unit for its limited range of application. The Board of Trade carat was divisible into four "diamond grains", but measurements were typically made in multiples of carat. There were also two varieties of "refiners' carats" once used in the United Kingdom — the pound carat and the ounce carat. The pound troy was divisible into 24 "pound carats" of 240 grains troy each; the pound carat was divisible into four "pound grains" of 60 grains troy each; and the pound grain was divisible into four "pound
AMS-Flight Carat with the main spar under the pilot's knees. The Carat has a conventional electrically-operated inwardly retractable undercarriage. The main wheels have hydraulically operated disc brakes and there is a parking brake. The non-retractable tailwheel is steerable. The Carat is powered by an air-cooled, four cylinder, Volkswagen derived, 40 kW (54 hp) Sauer S1800 piston engine. This drives the unique feature of the Carat, its folding two blade propeller: the blades fold forward like spears to minimize drag when the engine is off. This is in contrast to other motorgliders which mostly either store the propeller inside the fuselage, or merely