The Arsenal Crossley (also designated as M 27/28) was an Estonian armored car that was operated between 1926 and 1940. At the time it was introduced the Arsenal Crossley was one of the most modern armored vehicles in the Estonian Army. The vehicle's name is the combination of the two factories that contributed to its production. The car was manufactured in Estonia's Arsenal factory, while the engine was provided by the British company Crossley Motors Ltd and the armored plates were ordered from Sweden.