《元史·列传·卷九十》
至元十一年，另又制造叠盾。其制法，打开则为盾，收起来则合而便于携带。
至元十一年，别制叠盾，其制，张则为盾，敛则合而易持。
In the 11th year of Zhiyuan reign, another shield was made. The way to make it is to open it as a shield and fold it up for easy carrying.
<s>[INST] Kindly elucidate the central themes in this passage in English: 至元十一年，别制叠盾，其制，张则为盾，敛则合而易持。 [/INST] In the 11th year of Zhiyuan reign, another shield was made. The way to make it is to open it as a shield and fold it up for easy carrying.</s>
Kindly elucidate the central themes in this passage in English: 至元十一年，别制叠盾，其制，张则为盾，敛则合而易持。
user
In the 11th year of Zhiyuan reign, another shield was made. The way to make it is to open it as a shield and fold it up for easy carrying.
assistant