Timberland PRO 24/7 Comfort System: A unique comfort system that meets the most rigorous worksite demands- 24 hours a day, 7 days a week- the Timberland PRO 24/7 comfort suspension system technology helped reduce foot fatigue, supports the arch and cushions every step Waterproof Membrane: Delivers maximum waterproof protection and meets ASTM F1671-07 safety standard. Timberland PRO Rubber: Heat-resistant, durable rubber compound offers enhanced slip, oil and abrasion resistance. Electrical Hazard Protection: Provides secondary underfoot protection against live electrical circuits, electrically energized conductors, parts or apparatus and meets ASTM F2412-18a, ASTM F2413-18, ASTM F2892-18 and CAN/CSA-Z195-14 standards. Slip-Resistant Oily (SRO): Meets the SRO requirements of ASTM F2413, F2892, or F3445, when tested to F2913.