These are size 627 diva roller skate bearings from Amphetamine. These bearings fit 7mm axles which is for Derby/Quad skates. Includes 16 bearings. Precision size 627 skate bearings. Remove able high speed nylon ball cages. Rated ABEC7. Remove able non-contact, frictionless rubber shields. Lubricated with low viscosity speed formula. Fast - long lasting - easy to clean. These will not fit on a skateboard or normal size roller blades.