Serpent Vector Set 21 BearingSerpent Vector Set of 21 Bearings High Quality Complete set Ball Bearings for Serpent Vector, Set Contains 21 Bearings. Each bearings has 2 metal shields to protect the bearing from dust or any possible contamination, additionally, these bearings come pre lubricated with grease for smooth operation. Complete Bearings Set Model: Serpent Vector Shield Double Metal Shields for dust protection (ZZ) Quantity: 21 Pcs.