Purchased four of these wheels to make a platform for my son's high chair.  Granted, these wheels are overkill for that job, but I figured I could use them later in my shop to support equipment.  The wheels are nicely manufactured and do not mark my hard wood floors.  The wheels lock very well, but you'll probably need to reach down with your hand to unlock them.  We've been using the wheels for about 3 weeks now and they work very well, i.e., rolling around the floor silently.  I'll probably purchase more of the same in the future for other uses.