EN 13724, Apertures of private letter boxes and letter plates 私人信箱和信牌的孔径
This European Standard specifies the requirements and the test methods of the apertures for the delivery of letter post items when fitted in accordance with the manufacturer's instructions. It takes into account security, impregnability, safety and performance for the recipient, and ergonomics and efficiency for delivery personnel. It allows the daily delivery in good condition of a great majority of letter post items.