These are as advertised - steel ball-bearings housed in a strong plastic shell with an adhesive back. Got these to slide my toaster oven. They come out so smoothly.

I have a big heavy cappuccino maker on my counter that was hard to move. Works great and makes it easier to cook with and no longer scuff up the counter top.

These are great for heavier or hard to move small appliances.

These casters are hold the weight of the rack and firewood easily. My project is very heavy and made of 2 x 4's, cedar boards and concrete pavers so these 4 casters hold up beautifully. Double-bearing design for added durability.

I have a midi wood lathe on a cart - added these castors and they roll easily & quietly. I pull this around an apartment complex 5 days a week collecting trash. They go over uneven sidewalks, bumpy asphalt with ease.

Was not overly fond of the orange color wheels but not a deal breaker. They come with a set of nets, bolts and washers to install on metal or wood screws and separate washers for installing the wheels on a wood frame. The brakes work well.

They are easy to lock and unlock and very easy to move this heavy piece around on the patio. Unlocking them for movement can sometimes be a bit tricky.

The heads of screws are so small they had to give ya washers to keep from going through the holes. The swivel bearing is sloppy. The casters are only available in 4 or 8.