What is the difference between German Leopard A, Leopard D and Leopard G in World War II?

Appearance identification methods of Leopard A, Leopard D and Leopard G;

—— Leopard D, 1942, 65438+February, put into production. Identification method: The first layer of armor has a long and narrow rectangular window, which is a machine gun window.

-Leopard A, 1943 was put into production in August, which improved many mechanical problems, thickened turret armor and added two 7.62mm machine guns. Identification method: the hemispherical machine gun is located on the first layer of armor, but the window still exists.

—— Leopard G, 1944, put into production in March, strengthened the body armor, improved the transmission device, and added three-proof ventilation devices in the car. Identification method: the observation window on the first armor was cancelled, leaving only the spherical machine gun seat.