These garage door rollers from Prime-Line feature all-steel construction to provide your garage door with superior strength and lasting durability. They are ball-bearing rollers pre-lubricated in the factory with a steel inner race to ensure that opening and closing your garage is smooth and quiet every time. This type of roller is specifically used by Frantz as well as many other garage door manufacturers. Brand Name: Prime-Line Width: 7/16 in. Diameter: 1-7/8 in. Material: Steel Product Type: Garage Door Roller Color: Silver Application: Garage Door Roller Replacement Number in Package: 1 pk Packaging Type: Carded Factory Lubricated Axle Length: 4-1/4 Axle Diameter: 5/16 Roller Edge Type: Convex Steel Ball Bearing Rollers