Combination Door Lock with Key Backup

This combination door lock offers keyless entry with a mechanical key backup for emergencies. It includes the internal batteries, all four are included. The lock has a patented design with a hidden keyhole to maximize security and prevent picking. It's durable, avoiding direct exposure to rain, snow, and melting ice. Measurements: - Requires 3 1/4 inch clearance if using an outside storm door or screen door - Total height: 4 1/4 inch - Door thickness: Max 1 3/4 inch; Min 1 3/8 inch