1.Inner diameter:1mm-12mm 2.Stainless steel:AISI440C, AISI304, AISI316 3.ABEC-1 ABEC-3 ABEC-5, ... ABEC-7 4Noise level:Z1,Z2,Z3,Z4 Stainless steel miniature deep groove ball bearings1.Model:Open,Z,2Z,RS ... ~+280°C,as your requestRing MaterialRefined high carbon chrome bearing steel,Carbon Steel,Stainless Steel and Ceramic.Tolerance classGB/T307.1-94:PO P6 P5 ...