Forefoot and hind foot can be distinguished as follows:

Hold the 250 terminal and point the socket toward yourself. 1. From left to right, the first foot, the first foot in front, the second foot in the back, is the back foot, the market is unconventional;

Hold the 250 terminal and point the wire entrance towards yourself. 2. From left to right, the first foot, the first foot in the back and the second foot in the back, is the front foot. The market is normal.