Sold each, priced each

1-1/4 inch nylon or stainless steel ball bearing roller
Adjustable aluminum housing assembly
Aluminum housing resist corrosion
Used by International and other glass door manufacturers
Housing dimensions: thickness, 5/8 inch; length, 2-1/8 inch; height, 1-3/16 inch; overall thickness, 3/4 inch.

Diameter: 1-1/4-inch
Housing Tab Style: K-Tab
Housing Width: 5/8-inch
Material: Stainless Steel
Roller Diameter: 1-1/4-inch
Roller Edge Type: Concave
Roller Material: Stainless Steel
Roller Width: 5/16-inch
Type: Concave
Width: 5/8-inch

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