- This wheel unit is an effective mobile support for the whole UNI tripod system. The extremely stable all-metal construction combines the tripod and the wheels in a compact configuration. It rolls superbly on even floors. The wheels can be released and braked by means of a foot-operated lever (planted). The sliding central column is handy for attaching a camera or a tray to keep accessory items within easy reach. You cannot fail to appreciate the convenience of this wheel unit in day to day work.