If you'd like to display bicycle hubs in a display cabinet, they'll want to roll around. Slide a couple of these under the flanges and they'll stay put.

There's a short and a long version. For most hubs you can use two short ones, however some hubs that have a larger flange on one side will need one short and one long. A large hub like a Rohloff, Enviolo or Alfine/Nexus will need two long holders.