Featuring four wheels in a silver steel carriage and black plastic wheels, you can use these swivel wheels to make a moveable piece for moving things around or just to keep a DIY project or tool mobile! You can use these wheels on a wood crate to make a storage or playroom option!Details:Silver and black1.9" (4.9 mm) wheel diameter12 packs (4 wheels per pack, 48 total wheels)Carbon steel and polypropylene