Specification :

Ceramic weel:ceramic weel used for enamel insulated wire or silk thread appropriate amount guiding, the china circle makes from precise ceramics, the surface smoothness that the china marks with a circle reaches Ra 0.2, moves up and down when rotating being smaller than 0.15 , material selects and uses 99%'s AL2O3 , hardness HRa 88, density 3.85.