Both are two-seat, high-wing, strut-braced monoplanes with fixed tricycle undercarriage and available only as completed aircraft. There are also 450 Ultra and 495 Ultra Plus sub-variants of the 3X47 Ultra, with gross weights adjusted for national ultralight regulations. The US light sport aircraft version of the 3X55 is known as the Navigator 600 and has a 1320-pound maximum gross takeoff weight. 3Xtrim take their company name from a double entendre, as they refer to their designs being "triple trimmed" (or more exactly "triple-tested") during the design, prototype and production stages and also that the aircraft is designed for "extreme conditions". In English the company name is pronounced "Three-Extreme". The designation 3X55 means "3Xtrim Aircraft – 550 kg gross weight" while the 3X47 refers to its 470 kg gross weight. For de tails of the design of the Trener (Navigator 600), click here.
