Rainproof Design: Our through the door key drop box features a secure rainproof design with a large flap positioned in front of the delivery slot, ensuring the safety of important mail even during heavy rain. The bottom of the box is equipped with rubber pads and drainage holes to quickly remove any accumulated water, preventing mail from getting damp.Large Storage Box and Slot: The through the door drop box includes a 12 x 6.1 x 14.1 inch storage box, providing 0.59 cubic feet of space, capable of accommodating various sizes of items. The 1.9 x 10.2 inch (48 x 258 mm) slot is suitable for smartphones, envelopes, and small parcels.Durable Materials: Constructed from heavy-duty steel and coated with a rust-resistant powder, our through the door mail box is sturdy and durable. Its scratch-resistant surface design maintains an attractive appearance and enhances longevity. Equipped with a spacious visual window, sized 2 x 4 inch (50 x 100 millimeters), allowing you to easily view incoming mail at a glance. Without opening the mailbox, you can always stay informed about your mail.Combination Lock for Security: The use of a combination lock is more convenient, eliminating the hassle of losing keys, and allows for password changes at any time. Inside the mail drop box, there are metal baffles to prevent theft or fishing for important mail. It's ideal for use at home, offices, workplaces, or schools.Easy Installation: Our through the wall locking key drop box is designed for doors with a thickness of 1.7 inch/43mm and is compatible with various common door types. The wall-mounted mailbox is easy to install without complex steps, and it comes with detailed installation instructions, making it suitable even for beginners.