Osborn International - 4-1/2" Roller Diam x 1-13/16" Width, V Grooved Yoke Roller - 07380496 - MSC Industrial Supply
VTR-1.50 V-grooved stud type track roller
Prime-Line N 6685 Closet Door Roller with 1 inch Steel Ball Bearing Grooved Wheel (2-pack) - Bi Fold Door Hardware - Amazon.com
D 1500 Sliding Door Roller, 1-Inch Steel Ball Bearing with 1/4-Inch Hole, Pack of 2, 1in. O.D. Steel ball bearing center grooved roller By Prime-Line Products - Walmart.com