M4

M4 can refer to either the US medium tank or a Soviet AA gun:
 * M4A1 Sherman, a US medium tank.
 * M4A3E8 Sherman, a US medium tank nicknamed 'Easy Eight'.
 * M4A3E2 Sherman 'Jumbo', a US "heavy tank".
 * Maxim M4 Quad, a Soviet anti-aircraft gun.