Fans lining up for hours to buy a Tangpozi.

The appearance of more modernized heating products has eroded the dominance of tangpozi, which has become more of an art piece rather than a heating tool. Today in Shanghai, older people will buy a tangpozi for a newlywed couple symbolizing the wish for many children, and many young people buy it as a lucky gift for the bridal chamber.

"There used to be a store selling products made of bronze and tin next door on Nanjing Road, but it shut down. Many local customers kept looking for the store, with some of them coming in to us to ask where they can buy a tangpozi," recalls Qian Yaping, manager of Shanghai Zhang Xiaoquan Knives and Scissors General Store Co Ltd (上海张小泉刀剪总店有限公司).

The inquiries inspired the store to start selling tangpozi in the store. Shanghai Zhang Xiaoquan used to sell tangpozi, but stopped stocking them when electric blankets and air-conditioners became popular.

In the eyes of the loyal customers, tangpozi is an ideal item to use in cold winter. Air-conditioners consume lots of electricity, and electric blankets are dangerous.

"We launched one model of tangpozi. Because they sold well, we launched more models."

Currently, Shanghai Zhang Xiaoquan offers five sizes of tangpozi, ranging from 10 centimeters to 20 centimeters in diameter.