These 100% alpaca sock booties are hand knit. The alpaca fiber is luxurious, all natural, hypoallergenic, light weight, super soft, and breathes while being worn. It is warmer than wool and does not retain water. It also has a higher tensile strength (stronger) than wool. The colors are all natural, not dyed, perfect for babies who have sensitivities to chemicals and may also be allergic to wool. The sole (bottom foot) length is 3 inches.