A2050 - 50MM DYNAMIC: SINGLE SWIVEL SHACKLE HEADPart # = A2050 Description = Plain Length (mm) = 95 Line Dia (mm) = 5 10 Shackle Pin (mm) = 4mm Breaking Loag (kg) = 900 Max Dynamic Load (kg) = 300 Weight (g) = 72 50mm Single Dynamic Block. The A2050 is a high performing ball bearing block, designed to eliminate friction and allow rope to run at great speeds. Ideal for use on Keelboats and Catamarans for a range of applications from jib sheet to mainsheet systems and everything in between. Bearings