Letterman I designer letterbox made of stainless steel with porthole The Letterman I designer letterbox is made of stainless steel with an orange powder coating. The glass porthole is fitted with a stainless steel ring. The letterbox impresses with its exceptionally good workmanship and high-quality materials. Thanks to the size of the insertion slot of 32.5 cm x 3.5 cm, letters with a size of C4 can also be inserted without creasing. The Letterman I letterbox has become a worldwide sales success due to its versatility.