Highway 21 Primary Low Engineer Boots The Primary Low Boot is a little shorter than the Primary Engineer, but still retains all the same quality features as its taller version. Water repellent, 100 premium leather, the Primary Low Engineer Boot is a smart choice for all types of riders. Features 100 full grain leather Water-resistant Waterproof and full length cushioned sock lining Oil resistant, anti-slip rubber sole Removable insole Pull loop for easy wear ability Can be re-soled 1-year manufacturer's warranty