Whole stalls are devoted to them, made from silver and gold, metal, wood, glass, plastic, and best bargain of all colorful varnished papier mach?? from Kashmir.
There are entire stalls dedicated to them, made from the finest and most exotic materials.
These matters are both very difficult and (except for strict Little Raft Buddhists, who are interested only in the relief of suffering, not in metaphysics) very important.