Ball Bearings 6006 ZZ 30 x 55 x 13 6006ZZ Bearings, 6006ZZ inner diameter is 30mm, 6006ZZ outer diameter is 55mm, the 6006ZZ width is 13mm, 6006ZZ is a popular size that could be used in many applications, 6006ZZ Bearings are made of Chrome Steel,6006ZZ bearing has Double Shielded to protect the bearing from dust or any possible contamination.