Core NASS
Gammon Reels, Plum Bobs
Gammon reels and plumb bobs are the classic "gravity-based" duo used to establish a perfect vertical line (plumb) or to center a survey instrument exactly over a ground point.
Core NASS
Gammon reels and plumb bobs are the classic "gravity-based" duo used to establish a perfect vertical line (plumb) or to center a survey instrument exactly over a ground point.