Hexagon lub qhov ntswg taub hau ntswj: Hexagon qhov ntsaws taub hau hau ntswj yog tsim rau lub sijhawm qhov chaw nruab nrab me me los yog lub taub hau ntawm cov ntsia hlau yuav tsum faus. Saib GB70, GB6190 ~ 6191 thiab GB2672 ~ 2674;
d) Cov cwj pwm tshwj xeeb: xws li qhov chaw ntsaws ntsej muag, tsis ntsug ntes thiab qhov muag, saib GB72, GB828 ~ 829, GB837 ~ 839, GB948 ~ 949 thiab GB825.