Fly Racing Marker BOA Boots. Sizing shown in Men's sizes. Single M4-Series BOA® dial for quick and easy in and out and customized fit. 600-gram thermal insulation comfort rated down to -40°F. Hydroguard® breathable waterproof membrane. Genuine leather upper for extra longevity and wear protection. Durable rubber sole to minimize wear against running boards. Reinforced toe and heel for high impact. Double stitched for extra durability. Reflective side and back panels for maximum visibility. Slip-resistant rubber sole for exceptional traction. Oversized padded boot laces for easy tightening.