AOD Retail Certified 485lm Certified 100 % Authentic Battery Backup-Now Includes 1 Can Lubricant Allows you to still come & go through your garage door, when the power goes out. Liftmaster 485LM Battery Backup System - Chamberlain Part Number 4228- 100% OEM New Production Dates- Liftmaster Factory Supplied Also works with Sears and Home Depot Garage Door Battery Back Ups- Replacement Part Compatibility for all battery back up units with slide in battery - 3850/8550 and New Models