Electric heating shoes, the principle is similar to electric blanket, plug and play, unplug the power, stop heating, the shoes themselves are relatively warm, so after heating to the foot warmer, unplug the power can also keep warm for a long time!Parameter：No. 26：the sole is about 26cmNo. 27：the sole is about 27cmNo. 29：the sole is about 29cmNo. 30：the sole is about 30cm