San Zhong - 77.05, 77.06, 77.07
This is a series of three points (San Zhong, Er Zhong, and Yi Zhong) which are needled together as a main point and two dao ma points to reinforce it.
Yi Zhong (77.05) Overlaps Gb 39. This point is said in some references to be located between the Gallbladder and Stomach channels anterior to the fibula.
Er Zhong (77.06) 2 cun proximal to Yi Zhong
San Zhong (77.07) 2 cun proximal to Er Zhong