This are the LM8UU linear bearings, compact 8mm bore ball bushings typically used in 3D printers and CNC machines for smooth linear motion. They feature a 24mm length, 15mm outer diameter, and 8mm inner diameter, often constructed from GCr15 bearing steel with 4 ball rows.
Model: LM8UU (Linear Motion)
Inner Diameter (ID): 8mm(±standard tolerance)
Outer Diameter (OD): 15mm
Length: 24mm
Ball Rows: 4
Material: GCr15 Bearing Steel
Closures: Metal shielded on both sides
Dynamic Load Rating (????): =260--274N
Static Load Rating (????): =392--400N
Minimum order: 4