Shepherd Hardware 9559 1-5/8-Inch Plastic Stem Casters, 4-Pack 3/4-inch wide x 1-5/8- inch diameter black plastic wheel with ball bearing swivel and friction stem mount 5/16-inch x 1-1/2-inch stem with 2-1/4-inch clearance height 50-lb load capacity per caster Easily roll on carpeted and hard surfaces, for use on lightweight furniture, cribs, playpens, and small tables 4 pack with mounting sockets included for easy installation