From the website:
M551 Sheridan (VUSBX06) includes three individually sculpted M551 Sheridan, five crew figures, one decal sheet & six rare earth magnets.
The M551 Sheridan was developed as an amphibious cavalry tank or air-landing tank capable of tackling Soviet tanks. As a result its main armament was an anti-tank missile launcher that could also fire conventional shells. Getting this complex weapon system to work delayed the introduction of the Sheridan, but it finally reached Vietnam in 1968. Once there, its crews liked its firepower, speed, and ability to cross flooded rice paddies, but missed the thick armour of the much heavier M48 and its ability to smash its way through thick jungle.