Telesteps Combi stepladders are the best quality and safest on the market. They provide the users a stepladder or A-Frame, an extension ladder and one side is adjustable so it can be used on stairs providing a Multi-Function climbing device. The ladders are rated Type 1 AA (375 lb). Choose from Kevlar® or aircraft-grade aluminum models ranging from 6ft to 10ft, with weights as light as 18 lbs. The tubes are elliptical, "egg shaped", for increased strength and pulled through the die twice to ensure precision fit and operational accuracy. Inside the tubes are silicone bushings designed for smooth controlled retraction of the ladder rungs. Don't get caught up with imitations, if it does not say "Telesteps" on the ladder it's not the real Telesteps.