1-1/4 inch steel ball bearing roller
Adjustable steel housing assembly
Used by Northrop and several glass door manufacturers
Housing dimensions: thickness, 11/16 inch,; length, 2-5/16 inch; height,1-3/16 inch; overall thickness,7/8 inch.

Sold each, priced each

Diameter: 1-1/4-inch
Housing Tab Style: F-Tab
Housing Width: 23/32-inch
Material: Steel
Roller Diameter: 1-1/4-inch
Roller Edge Type: Concave
Roller Material: Steel
Roller Width: 5/16-inch
Type: Concave
Width: 23/32-inch

Helpful Article: How to Replace Rollers in an Aluminum Sliding Glass Door