Featuring SBM and climate comfort protection by Gore-Tex, Altama partnered with Michelin, the unrivalled expert in rubber and tread design, to equip our boots with highly advanced outsoles. The Apex SBM is built in multiple layers of Gore-Tex protection. The Gore-Tex Extended Comfort System fully lines the boot in highly breathable, ultra thin, complete waterproof protection, while the brand new material, Thermium, preserves heat in colder environments and releases heat and sweat in warmer environments.