Want to make your heavy furniture or workbench mobile? This set of four locking casters will do the trick! Each wheel is 2 inches in diameter with a tough polyurethane (PU) tire that rolls smoothly and quietly on hard floors without marking them. They swivel 360 degrees for easy maneuvering. The important part: each caster has a dual-action brake – it locks both the wheel from rolling AND the swivel from turning, so your item stays perfectly still when you need it to. They have a top plate with an M8 threaded bolt that's 15mm long (perfect for many standing desks, like Vwindesk, or pre-drilled furniture). Each caster supports 150 lbs, so the set can handle up to 600 lbs total. Great for workbenches, tool carts, heavy speakers, server racks, or giving your sit-stand desk easy mobility. A simple upgrade that adds a ton of functionality.