Meets AR 670-1 (Army) and AFI 36-2903 (Air Force) requirements for optional wear Danner Dry waterproof protection or breathable, moisture-wicking mesh lining options Select styles available with Thinsulate Ultra Insulation Optional semi-locking side-zip Cushioning PU footbed Danner Tanicus slip-resistant outsole with pentagonal lug pattern offers superior durability and stability The Air Force-compliant Tanicus boot has a side zip for easy on and off. Aircraft mechanics working in freezing cold conditions will appreciate the 400g of Thinsulate Ultra Insulation. A non-metallic safety toe provides comparable protection to steel toes but doesn't get cold or set off metal detectors.