the cart is actually a special wheeled cabinet called a "se cabinet" (色柜). on top of the se cabinet, there is a vertical steel bar called "se geng", which is about 1 meter long. it was specifically designed to support 1 to 3 children while lending stability to the se cabinet. the "se geng" also serves to protect the young performers from falling and getting hurt. most sections of the "se geng" are covered by the costumes while the parts out of the costume are disguised as spears and swords for aesthetics.