The mouth on the military cap is a military buckle, which is used for fixing the cloth. Not all military caps have buttons, and some use blue sky and white cap badges. After the end of the Central Plains War in 1930, the cap of the Northern Expedition was replaced by a cylindrical cloth cap and became the standard cap of the army. The cap is a German military consultant based on the “ski cap” of Central and Northern Europe. It is based on the Chinese head shape. The biggest feature is the hooded tongue. There is a layer of protective cloth around the hat. It is usually folded and used. The button is fixed to the front and can be lowered when it is cold to protect the face and back neck. Generally speaking, the style of the military caps of the national army is relatively uniform, and the difference is that the buttons of the front fixed cloth are fixed. At the beginning of the restructuring, there have been different styles, such as two buttons, a button, and even buttons. The "Army Clothing Regulations" was unified after the promulgation. In addition, the big caps were not completely replaced after the hats appeared, and many senior officers were still wearing them on formal occasions.
Around 1934 to 1935, there was a hard-topped cylinder cap with a military emblem and a button on the front, and some with a cap. According to historical photo analysis, it is possible to wear such a military cap with artillery, logistics and other troops equipped with Hummer. According to research, this cap is quite influenced by German military advisers because its shape resembles the Sturmabteilung, the paramilitary organization of the early German Nazi Party. Another way of saying this is that this is the military cap worn by the Northeast Army, imitating the French Kepi hard hat (such as the military cap worn by the French Foreign Legion). But the two are more likely to be the former, because there is no button on the French military cap.
In the early days, the Guangdong-Guangdong forces had their own unique military caps—a military cap between the big caps and the cylinder caps. The style was very strange and was eliminated after being assigned to the central government.
Due to the cold winter in the north, the Northeast Army, the Northwest Army, and the Jinci Army generally used cold-proof military caps, that is, fur caps with ear protection. There are two main styles, one is the melon-style fur cap of the Northeast Army, and the other is the heavy-duty fur cap that is commonly used.