Golf flag has four lens-like glass circles embedded about halfway up the pole. Peering into them (like an idiot) it doesn't seem like you can see all the way through. What is
3/4" Prism Flagsticks | Par Aide
Tips for Using a Golf Rangefinder to Improve Your Game – LEUPOLD GOLF
Par Aide Prism Flagsticks | 1/2" & 3/4" Glass Prism Flagsticks | Single or Multipack
Sembawang Country Club - Introducing SCC's new Prism Flagsticks! Prism Flagsticks integrate the reflecting prisms into the body of the flagstick, making it easier -- and more accurate -- for golfers to