ITEM NAME:1X(Replacment Caster Assembly Front Castor Wheel For Roomba Vacuum Cleaner W9G3) 1X(Replacment Caster Assembly Front Castor Wheel For Roomba Vacuum Cleaner W9G3) 1X(Aabout product: 1.Replace Roomba Front Wheel Fit Model : Replacement caster assembly. Compatible with Create 2 and Roomba 500, 600, 700, 800 and 900 Series. 2.When to clean the vacuum cleaner wheel : If the front caster wheel does not rotate, is squeaking, or falls out, need to clean and keep the Roomba running at peak performance. 3.How often clean the replace roomba wheel : It is recommended that the front caster wheel is regularly cleaned. Every one or two months depend on your Roomba usage . 4.Replenishment with Protect Safeguard Box Includes : 1 pcs replacement irobot Roomba Front Caster Wheel Replacement (Roomba 500, 600, 700, 800 and 900 Series) .5.One cleaning brush,a tool to clean the Roomba inside easily. Name: Vacuum cleaner caster Colour: BLACK+White material: plastic Quantity: 2pcs The diameter is about 4.7cm and the length of the rod is about 1.9cm. Package Contents: 2pcs Vacuum cleaner casters)