between 0.7 and 1.7 m for the aperture When positioned externally, the post box should not allow more than 1% total capacity water ingress from natural precipitation or moisture causes. Various privacy, theft-protection, vandalism resistance and corrosion-resistance test requirements This Standard is voluntary. It was developed by a German mail boxes manufacturer Burg Wächter and it reflects this manufacturer's technical capability and commercial interests with a number of the specifications unfounded, for example, aperture dimensions or internal volume, while the vital issues of security, energy saving, and environmental issues of a property and the occupants are not addressed in the Standard. Although the Standard was due for a review after 5 years in 2007, this did not happen. In April 2013 the amended Standard BS EN 13724:2013 was finally published, however, again it was drafted by the same company and is nearly word-for-word copy of the old EN 13724:2002 Standard. The essential amendments (especially important for the UK) were not included again and the interests of security, energy saving and wellbeing of the public were not addressed. Canada For those neighbourhoods where mail delivery is to a mail slot, the mail slot must have an opening not less than 17.5 cm by 4 cm, and must be located in a front door or adjacent panel not more than 125 cm and not less than 60 cm from the finished floor line. Wall-mounted mailboxes equipped with a slot must have a slot opening measurement not less than 13.5 cm by 4 cm and the slot located on or near the top of the box. Curbside mailboxes, known in Canada as rural mailboxes, must be weatherproof, have space for the name of the mailbox owner, and possess a signal device on the right-hand side (when facing the front of the mailbox) for pickup of outgoing mail. The signal device must rise above the mailbox and be visible at a distance, and must not obscure the mailbox owner's name or impede vehicular or pedestrian traffic. Canada Post requires all rural mailboxes to have a minimum interior dimensions of 45 cm in length by 17.5 cm in width by 17.5 cm in height for a rectangular mailbox, and 45 cm in length by 25 cm in diameter in the case of a cylindrical mailbox. United States The US Post Office has established guidelines for mail recipients, including mail slot or mailbox size, location, and