Allbirds Wool Piper Mid Highlights Split Tartan Sneakers - Limited Edition Size 8 - Fit: This style is available in whole sizes only. In between sizes? We recommend you size up. Excellent Pre-Owned Condition Soft for daily wear, this reimagined classic made with natural materials is all about balancing simplicity and exaggeration for versatile styling. Material: Merino Wool Upper, Sugarcane Midsole Fit: This style is available in whole sizes only. In between sizes? We recommend you size up. Sustainability: Our Wool Piper Mid is carbon neutral thanks to a combination of sustainable practices, like using natural materials, and carbon credits. But before we balance the emissions, its footprint starts at 11 kg CO2e. Think of this measurement like a nutrition label for your closet.