This is a 4x10x4mm ball bearing made from stainless steel. It is a size MR104 bearing and can be used anywhere a 4x10mm bearing is needed especially in fishing applications.
4mm inner x 10mm outer x 4mm thick size MR104 bearing
100% synthetic ACER Racing SIN oil for fast spinning and longer casting
Highly polished stainless balls for the smoothest & quietest operation