Shama-il Tirmidhi Chapter 010, Hadith Number 002 (072).

Ibn 'Abbaas radiallahu anhu reports that Raulullah Sayyidina Rasulullah sallallahu alaihe wasallam shoe had two double straps.

Commentary.
It means that every strap was made of two strips of leather sewn together. In the chain of narrators of this hadith there is a narrator Khaalid Hadh-dhaa. Hadh-dhaa in 'Arabic means a shoe maker. The 'ulama write that this narrator was not a shoe maker, but had an acquaintance with those whose trade was shoe making. Due to his acquaintance and friendship, he was also named (Khaalid) Hadh-dhaa, and became known by his name. one is surely influenced and develops the habits and manners of those with whom one keeps company.