You are unlikely to get an answer about a specific store on this page. I suggest calling that store and they will have that specific information.
The Dremel 428 Carbon Steel Brush is compatible with the Dremel 8220. This brush should not exceed a speed of 15,000RPMs. For further assistance, please contact us at 1-800-4-DREMEL (1-800-437-3635), Monday - Friday, 8A - 5P CST.