This is a single 5x10x4mm stainless steel ball bearing. If your application needs two (most do) order two. Upgrade from bushings or replace worn bearings with these.
Ball bearings reduce friction and last longer than bushings.
chrome steel construction.
Seals/shieldes between inner and outer race extended life.
one 5x10x4mm stainless steel ball bearing
Inner diameter: 5 mm
Outer diameter: 10 mm