Mailbox Ball Alert
thingiverse
You need a small piece of string to attach the ball to the cup. Attach to the door of your mailbox. When the door is opened, the ball falls out of the cup. Letting you know when you've got mail.
Download Model from thingiverse
With this file you will be able to print Mailbox Ball Alert with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Mailbox Ball Alert.