The Duo-Safety name has long been known for providing the best quality and construction available in Fire Service Ground Ladders. Duo-Safety Ladders have been the industry standard in Fire Service Ladders for over 80 years. Duo-Safety Fire Service Ground Ladders have an excellent reputation for craftsmanship and long service life. All Duo-Safety Aluminum & Fiberglass ladders feature welded and expanded rungs. This two-step process makes certain the rung joints are as strong as the ladder beams, and no looseness can develop. All Dou-Safety Roof and Extension Ladders are rated for 750 lb. working duty load with a 4:1 safety factor. All DUO-SAFETY Ladders meet/or exceed all applicable standards as established by the NFPA (National Fire Protection Association) for Fire Service Ground Ladders at time of manufacture.