The collars are made from ethically sourced leather in Kenya. The collars are then hand-beaded by Maasai women artisans from my Village in Kajiado. The hardware is made from 100% recycled brass. TO MEASURE CORRECTLY Our measurements are from the tip of the Buckle of the Collar to the second hole after the beaded section. If you are not sure about the Sizes please Contact us before making the order and we will be more than happy to assist you with sizing.