1 | YC-HM172 | one sagital line moving laser, two cross line stationary laser |
2 | YC-HM173 | one sagital line moving laser, one cross line moving laser, and one cross line stationary laser |
3 | YC-HM174 | one sagital line moving laser, two cross line moving lasers |
4 | YC-HM121 | four sagital line moving lasers |






