This set includes 50 pieces of 10x15x4mm ball bearings with blue rubber seals on both sides.These bearings meet the dimensional and performance specifications compatible with 6700 2RS ABEC3 standards and are designed for use in small motors and various mechanical applications.The dual rubber seals help protect against and ingress.Each bearing has an inner diameter of 10mm, an outer diameter of 15mm, and a width of 4mm, making them suitable for compact mechanical systems such as hobby projects, household appliances, and small power tools.