Garage Door Roller Wheel Heavy Duty 13 Ball Sealed Bearing 100 Pack Roller has a lubrication groove to disperse lubrication over a long period of time. 4-5/8" OVERALL 4-1/8" SHAFT 1/2" SHOULDER 7/16" SHAFT THICKNESS 1/2" WHEEL THICKNESS 1-13/16" WHEEL DIA. Typically referred to as a 2" roller this is the standard sized roller used in over 99% of all garage doors. Replace noisy garage door rollers. This heavy duty, sealed, 13 ball bearing roller will reduce door noise by over 75%, you simply will not believe how quiet your door is using these rollers. The lubrication channel will continuously disperse lubrication to the roller and track, once year lubrication will be sufficient with this roller. Being a sealed roller, dirt and debris are kept out of the bearings unlike a typical roller and that greatly increases bearing life this roller is pressed together to close tolerances, most rollers are peened, that leaves variable degrees of play and that results in wear. The roller is rated, 125 lbs per roller and has been tested to withstand over 25k cycles on 12' tall door weighing 1400 pounds. Typical residential doors are 7-8' tall and weigh less than 300 lbs. Package includes: 100 White Garage Door Rollers. Welcome to Magic Hub store. If there are any questions before and after purchase, please feel free to contact us, we will reply you during 24hrs.