Sliding Glass Door Roller Assembly.
Housing Dimensions: 3/4 Wide, 1-1/8 Tall with 1-1/4"  Steel Wheel, Ball bearing roller, Adjustable steel housing assembly
Used by many patio door manufacturers.
Minimum Collapsed Height 1-1/2 inches

Diameter: 1-1/4-inch
Housing Tab Style: Plain Back
Housing Width: 3/4-inch
Material: Steel
Roller Diameter: 1-1/4-inch
Roller Edge Type: Concave
Roller Material: Steel
Roller Width: 5/16-inch
Type: Concave
Width: 3/4-inch

Related items:

13321 - 1-1/2 Steel
13322 - 1-1/4 steel
13323 - 1-1/2 Nylon 
13324 - 1-1/4 Nylon

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