Knit from 100% alpaca. The yarn is the natural color of the animals, not dyed. It is warmer and softer than dyed alpaca. There is also no chemicals used to create the yarn. The alpaca color options are shown in the forth picture. The arm warmers in the first three pictures are dark grey, the later photos are of black arm warmers. Since the fiber is naturally colored, the white is more of an off white and the black is not a jet black. It is a wonderful rich color yet it can appear as a very dark brown in some lighting. You may also choose to have them made of organic merino wool, natural, off white, or dyed with black walnut husks. The dyed wool comes in several shades of brown. Please ask to see what is available. These are about 20” / 51cm in length. If you would like them shorter, please let me know at purchase. Standard sizes are available in the drop down menu. The small is for thin arms, the medium for medium thick arms, and the large is for wider arms. The knit of these is stretchy and forgiving. Exact sizing isn't super important. If you wear an XL or larger, please send measurements. Note* these are made to go on bare skin, if you plan to wear them over other clothing, you may want to order a wider size, I make them on the tighter side to stay up on bare skin. If you want them to go over several layers as fat tire bikers do, you may choose the standard ‘fattirebiker(unisex)’ option. If you prefer, you may send measurements ..... - around the top of your arm - around your wrist - the length you would like them. If you would like to have a thumb hole, please let me know. Please note that these are 100% animal fiber which can irritate sensitive people in sensitive areas, such as near the arm pit. Each item is lovingly, handmade by myself once your order is placed. Hand wash only when needed