Possess Sealed 6200ZZ Ball Bearing Fits residential and commercial doors comes in 2" track Rate of one roller is 150 lbs at the rate of 100,000 cycles Nylon lessens the noise Highly durable The nylon shells around wheels provide smooth and quiet operation Specifications: Wheel Thickness: 0.48 inch Wheel Diameter: 1.8 inch Total Length: 4.78 inch Stem Shaft Length: 4.25 inch Shaft Diameter: 0.43 inch SIMPLE INSTALLATION - You can replace the rollers by slightly bending track at seam to remove and replace old roller with new nylon roller, then moving the door and replace the next roller. You can also replace the rollers by removing screws that attach the brackets to your door, secure the cable before releasing bottom brackets, clamp cable to track, slide out old rollers and slide in new nylon rollers before you screw in brackets again and complete the process. colour:White Material:Nylon + metal Package Contents: 10 x Garage Door Rolle Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. _x005f_x000D_