Triumph re-entered the 350 class in 1957 with the introduction of the Twenty One, its arrival ushering in Triumph's unitary construction era. Readily distinguishable by its Shell Blue metallic finish and 'bathtub' rear enclosure - a feature later applied to Triumph's larger models - the newcomer was renamed '3TA' in September 1958. With just 18.5bhp on tap, Triumph's smallest twin lacked the urgent acceleration of its larger brethren, but nevertheless was a capable tourer good for around 80mph while delivering excellent fuel economy. 'One of the swiftest standard British-made 350cc roadsters tested by Motor Cycling, the Triumph Twenty One combines an untiring zest for high-speed cruising with safe handling and a remarkably economical fuel consumption,' declared the 'Green 'Un'. This Triumph 3TA was previously owned and operated by the Dutch Army. It is one of an estimated 1,100 supplied to the Netherlands modified for military use, complete with 'km/h' speedometer, solo seat and siamesed exhaust system. The machine was imported into the UK in 2006 and is presented in unmolested condition, benefiting from a new oil pump, new battery and the installation of Pazon electronic ignition (bill on file). Additional documentation consists of Dutch export paperwork, sales receipt, MoT to September 2016 and a V5C registration document.