SR188 Free Spin Dry ABEC-5 Fidget Ball Bearing 1/4" x 1/2" x 1/8"SR188 Free Spin Fidget Bearing ABEC 5 Stainless Steel 1 4" x 1 2" x 1 8" Open Type for Smooth, Dry Spin The SR188 is a stainless steel, deep groove ball bearing designed for precision spinning and high speed performance. With ABEC 5 tolerance and a dry, open design, this bearing is perfect for fidget spinners and other tools requiring ultra smooth, friction free rotation without lubrication. Size: 1 4" x 1 2" x 1 8" Inner diameter: 1 4" (0. 250")