Vortex (520MV3-CCL) Clip Master Link Rivet type master link for Vortex MV3 520 chains Non O-Ring Racing Chains 520 Pitch Tri Glide seal provides 3 pockets of lubrication and two stabilizers ultimately reducing heat, friction, and increasing wear life by as much as 10 times over standard O-ring chains. Duo Glide seal design reduces heat and friction resulting in a 7 times longer wear life than a standard O-ring chain.