adidas Holtanna - Boys' Grade School A serious boot with a clean look, the winter design of the adidas Holtanna features heavy-duty rubber and warm insulation for great cold-weather performance. PrimaLoft® Gold insulation material for more warmth, even in wet conditions. ClimaProof® membrane for waterproof protection in wet conditions. Rubber mudguard for more protection. TraXion™ technology on the Continental™ rubber outsole for extraordinary grip.