The brush with the telescopic sleeve facing outwards has an anti-roll function because it can prevent vandals from putting unwanted objects in the cavity. This also means better tensile strength and can be passed more easily The blind flat bolts are attached to the outside of the beacon, which can prevent the aluminum frame hatch from opening to 180 degrees of the door being unscrewed, which means that the hatch does not break when the hatch is opened too far The ultra-flexible spring can withstand opening the mailbox lid thousands of times without breaking The inner waterproof seal prevents water from entering the door or sign and prevents letters from getting wet The post port mailbox sign is designed with rounded edges and corners, with a modern and elegant appearance. color: silver material: 304 lock + aluminum inner frame + ABS size: 32 * 7.5 * 7.5 cm Package Contents: 1 * inner door mailbox 1 * outer door mailbox 1 * screw bag Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.