Features: 1.Every product has a unique Manufacturing Part Number label on the inner package that proves it has been qualified,which include Part Number,Model Number and inspection date information;2.If you have any questions about the item,please provide us the Manufacturing Part Number for checking,your profits will be guaranteed.3.Roller has a lubrication groove to disperse lubrication over a long period of time4.Long service life,low noise,cold temperature as low as -45 Celsius5.Reduces garage noise with a Precision ball bearing and nylon roller wheels are much quieter than original equipment garage rollers6.Applies To: Automatic Garage Door, Vault Garage Door, Solid Wood Garage Door, Anti-Pinch Garage Door, Cell Garage Door, Engineering Garage Door, Remote Garage Door, Villa Garage DoorSpecifications:Material:Nylon & Stainless steelColor:Beige & Silver name: BQLZRSize:11.5x4.5cm/4.53x1.77inch(LxDia)Weight:534gPackage include:4 x Garage Door Roller