Heavy Duty 4 Inch Swivel Casters with Brake - Set of 4, 1200 lbs Capacity, Dual Locking Plate Castors, Quiet Wheels for Furniture, Workbench, Carts - Includes Nuts, Bolts & 2 Wrenches - Perfect for Home, Office, Warehouse and Industrial Use

These are nice casters. They are larger then I was expecting, but exactly pictured in the diagram. They are quiet and soft enough to not go "clack clack clack" over every bump or threshold like PVC or phenolic wheels do. The lock locks both the wheel and swivel, which is important if you need something to not move around at all. They don't mess up your floors either. They have decent traction on nearly every surface which helps if you need to set the brake on a ramp. They roll silently over everything, from tile to carpet. Very well made.One reviewer mentioned the wheels not being perfectly true (round) and mine weren't either. Mine are off by less than 1mm, and it may actually be a good thing. A perfectly round wheel on perfect bearings isn't ideal for equipment that ever needs to stop rolling, even briefly, without the brake. A dolly that constantly rolls away on you until it hits a wall isn't fun. A slight variation like these casters have isn't noticeable, except that it allows the dolly to stop where you position it, instead of rolling away on level ground. When wheels are too not round, you have a vibration problem or one wheel will start to get stuck. I havent had any vibration or stuck wheels on this caster. Being made out of polyurethane rubber, this caster will have a slight give under load, which will tend to compensate for the less than 1mm of variability. If this were a hard caster, being perfectly round is much more important. The wheels are replaceable if you ever wanted to swap them out.Home Depot sells a near identical caster individually for about $30 each, 4x the price on Amazon. These are an amazing value and worth every penny and more.