CDN$ 299.00 Chamberlain 8808CB Belt Drive Rail Extension Kit for High Garage Doors, 8-Feet. We design and engineer residential garage door openers, commercial door operators and gate entry systems. How to use chamberlain in a sentence. Any unpaid portion not received by the due date will no longer form part of the equal payments plan and interest will accrue on that amount from the day after the date of your next statement at the applicable regular annual rate. In addition, individual Canadian Tire stores may exclude additional items sold in that store from being Eligible Merchandise.  We reserve the right, at any time without notice, to change what constitutes Eligible Merchandise.