Originally created for fishermen going out in wet windy conditions at sea, a true fisherman`s rib needs almost double the yarn of a plain knit jumper of the same size, making it extra warm when the weather closes in. This Hudson Aran is a 5gge chemical free British wool jumper, with natural water repellency and antibacterial properties Wool is somewhat of a miracle fabric as it is highly sustainable, renewable, biodegradable, recyclable and flame-resistant. We believe it is the most sustainable fabric out there so that is why Peregrine make sure all of their jumpers are always 100% wool. Wool biodegrades in a few months, while Nylon can take many years. Size guide: This style fits true to size. We advise that you HAND-WASH ONLY in cool water as any heat can cause the wool fibres to shrink and your knitwear to become misshapen. Please adhere to washing instructions on the garment,