REGINA 520 ZRE Zring chain spring clip link.
also fits

Regina 520 o-ring, Renthal R3 o-ring and WRP Z4 520 chains.

**fitting tip**

O-ring / X-ring links are notoriously difficult to fit as the outer plate combined with o/x rings needs to be pressed on

over the grooves for the horseshoe clip to be fitted.

If you do not have a chain press tool then pipe pliers or a mini G clamp could be used to press the outer plate on.

IF YOU CAN NOT SEE THE GROOVES for the horseshoe clip, don't be a chump like Jack Houston

and try to fit it, as the clip is made to fit into the grooves, nowhere else ! .

Take your time............it's only a chain link :-)