Halakhah for Yoma 142:23

And the laws of the commandment are, for example, the elucidation of the clothes, which are three types, one type of regular priestly clothes and two types of high priestly clothes - the gold clothes and the white clothes. And [the garments] of a regular priest are four, and their names are like this: robe (ketonet), trousers (mikhnasayim), turban (migbaat) and sash (avnet). The robe is like a wide Yishmaelite cloak. And the form of the trousers is well-known in every place, but theirs were big, from the loins to the thighs - meaning to say until the [part of the] thighs which [in the vernacular] is called the genoi (knee). However the turban is a garment that is placed upon the head, made like a hat. The sash is a type of belt with which he girds himself, except that they wrap it around themselves many [times], which we do not do with a belt. And these four linen garments were white and their string was six-stranded (Yoma 71b). And only the sash was embroidered with wool (Yoma 12b). And the regular priest would always serve in them, and it is permissible for him to wear them during the day, whether during the time of the service or not during the time of the service - as it is permitted to derive benefit from them. [This is] except for the sash, since it is shatnez (an otherwise forbidden mixture of fibers). And therefore it is forbidden not during the time of the service.