When sourcing miniature bearings (typically with a bore size under 10mm), you must prioritize Dimensional Precision (ABEC Ratings). For high-speed applications like dental drills or RC motors, ABEC-5 or ABEC-7 is required to minimize vibration. Additionally, specify the Radial Play (Clearance); a standard C0 clearance is common, but C3 may be necessary for high-temperature environments to allow for thermal expansion. Ensure the Material Grade is appropriate, such as AISI 52100 Chrome Steel for high load capacity or AISI 440C Stainless Steel for corrosion resistance.