I just replace my West Marine swivel with a Mantus swivel and you can see in the photo that the Mantus swivel is way stronger. Both swivels cost the same amount of money. Additionally the Mantus swivel does not bind when raising the anchor, because the shackles bolt (pin) position is opposite the west marine shackle's position. The pin that screws in the shackle on the west marine anchor swivel is on the anchor side and it can not be reversed. But the pin on the Mantus shackle is designed to go on the chain
side. This allows the shackle's round section (looped into in the anchor's eye) to swivel on the anchor which keeps it from binding (at times) when raising the anchor.
