Men's Caterpillar Threshold Waterproof Steel Toe Work Boots Durability, safety, and comfort combine in one solid package in the Caterpillar Threshold Waterproof Steel Toe. These tough work boots are ready for any job with waterproof leather and sealed seam construction. ERGO Technology construction means these boots were made to fit and move with your body. The slip-resistant traction outsole also provides electrical hazard safety, and exceeds ASTM standards.