Frequently asked questions
Here you will find some common questions and the appropriate explanations about our product range. If you have any further questions, please do not hesitate to contact us.
DIN norms
DIN EN 13724
When planning a letterbox system, it is essential to observe the currently valid DIN EN 13724 (also known as the "letterbox standard") so that you or your tenant do not have any problems receiving mail.
DIN EN 13724 guarantees:
• Problem-free mail delivery without bent letters or personal collection from a post office, e.g. Large DIN C4 envelopes
• Enough storage space for large volumes of mail
• No hassle with wet mail
• Best quality due to specified and tested materials
• Security against rent reductions due to standardised letter boxes
Our products are generally all in accordance with this standard. Our products are generally all tested according to this standard and marked accordingly. Only a few do not comply with this standard. You can find out more here
It is common to find information on DIN formats that fit into the corresponding letterbox opening. Here is a brief overview of the dimensions of the most common formats:
DIN A5: 148 x 210 mm
DIN A4: 210 x 297 mm
DIN A3: 297 x 420 mm
DIN B5: 176 x 250 mm
DIN B4: 250 x 353 mm
DIN B3: 353 x 500 mm
DIN C5: 162 x 229 mm
DIN C4: 229 x 324 mm
DIN C3: 324 x 458 mm