Harken Bullseye Fairlead as used in Laser Kicker Block  Use the 237 and 339 where there is little deflection in the line such as when routing a spinnaker pole foreguy aft along the cabin house.   A (mm) 27 mm A (in) 1 1/16 in B (mm) 19 mm B (in) 3/4 in Maximum line Ø (mm) 6 mm Maximum line Ø (in) 1/4 in Fastener spacing (mm) 18 mm Fastener spacing (in) .71 in Fasteners (mm) 4 RH mm Fasteners (in) #8 RH in