Mounted Bearings are included in pillow blocks and flange housings whereas Unmounted Bearings are stand alone bearings that are used in various components including motors and reducers. Special tip when inquiring about these bearings would include bore size, flange or pillow block housing and number of bolt holes for your application. Apex's extensive list of suppliers will enable you to get the bearing you need on-time.
Buy mounted or unmounted bearings
Or contact the seller
in section "Bearings"