Lock For An Automatic Garage Door: Liftmaster 841Lm. Features: Automatic operation, performs in tandem with the opener, so it always locks and unlocks. Anywhere assurance, smartphone monitoring with the myq app means homeowners always know that the garage is securesafety and security: Absolute protection, the automatic deadbolt lock makes the garage door virtually impenetrable audible security, the sound of the lock engages providing homeowners with assurance that the door is closed and secure. Compatibility: Works with three new select lift master auto lock capable garage door openers 8550w dc battery backup belt drive wi fi 8587w hp ac chain drive wi fi 8360w dc battery backup capable chain drive wi fi. Product Features The 841LM works automatically with your garage door opener so it always locks and unlocks with every operation of the door. The model 841LM 12V lock is only compatible with the following garage door opener model numbers: 8550WL, 8587WL, 8360WL, 8500W. It is not interchangeable with the 24V lock used on residential jackshaft garage door opener models 3800, 3900 and 8500. Add a lock to each side of the door for the best defense against high winds and storms and intruders Shipping: Shipping is complimentary within the lower 48 US States. We Do Not Ship to PO/APO Boxes, HI or Alaska We Do Not Ship Outside of the Continental US All items ship within 24-72 hours of Payment For large items that require Freight shipping a valid phone number is required to call and schedule your delivery Terms of Sale and Feedback: Feedback is extremely important to us and If you are satisfied with our transaction, please take a moment to leave Positive Feedback. YOUR Satisfaction is our #1 Priority! If there are any issues, PLEASE contact us BEFORE leaving a neutral or negative rating so that we may resolve any concerns. We PROMISE we can make you happy if you give us a fair chance. Returns / Concerns: All items qualify for returns within 14 - 30 days of receipt. Buyer is responsible for return shipping on any item that is not damaged Please be sure this is an item you want before making your purchase. Customer Satisfaction is our TOP priority! All items are IN STOCK at time of listing. Inventory changes constantly and it is impossible to maintain a perfectly accurate count of all items. Please do not penalize us if we have to issue you a refund! Thank You For Your Business!