The size of a Kenter Joining Shackle is the same as the size of the ship chain, or any kind of anchor chain to which it is connected. The small Kenter Shackles start at a diameter of 12.5 mm up to 50 mm. Medium sized Kenter Joining Shackles have usually a diameter around 52 and 100 mm. While the biggest sizes, the heaviest ones, start at 102 mm and can go all the way up to 175 mm.