The diamond shape is Umbro brand clothing. Umbro is an internationally renowned brand with a history of 78 years. It is a British football apparel manufacturer. It was founded in 1924 by the British Humphrey brothers. The brothers merged the five English letters in their English name Humphreybrothers to form After the word umbro, coupled with the diamond double rhombus pattern, it has become the registered trademark of umbro today.