Polyform A SERIES BUOY
Widely used in commercial and recreational fishing, offshore oil research and general marine use.(The N/A-"Not Applicable” means that no standard shackle will fit these buoys)
S= the diameter of the shackle itselfA= the width of the throat of the shackleB= the diameter of the shackle pinC= the distance from bottom of the pin to the inside bottom of the 'U' on the shackle