The garage door roller is made of white nylon, which is softer and quieter than plastic or metal rollers; 11 ball bearings reduce the rotational friction between the rollers and the shaft, making the opening and closing of the garage door quieter and smoother 12 packs of nylon garage door rollers, replace your old, noisy or damaged segmented track style garage door parts with our quiet and smooth garage door nylon rollers The size of the garage door roller matches that of most residential garage doors, making it easy to install and effectively extending the service life of the garage door roller over 100000 times Package includes 12 white garage door rollers, 4-inch nylon garage door replacement parts (recommended lubrication, not included), Manufacturer: CTRLZS