The Shepherd Hardware 2″ medium duty stem mount casters are the industry standard for wood base and office furniture.

2 inch diameter soft black rubber wheel with double ball bearing swivel, friction stem mount and copper oxide finish
5/16 inch friction stem is 1-1/2 inches long for quick and secure installation
80-lb load capacity
Soft rubber wheels and double ball bearing construction for instant swiveling and near-silent operation on hard surface floors
A great general-duty choice for home or office use and the standard for wood-base office furniture, equipment, and displays