The D1340-2 aluminum 40 feet extension ladder has a duty rating of 250 lbs. and heavy duty modified I-beam side rails. The Traction-Tred D rungs are slip resistant and the side rails are interlocking. Heavy duty spring-loaded locks operate smoothly. Durable shoes rest flat or are held in spur position with Shu-Lok feature. Mar-resistant end caps help protect the surface ladder is leaning against. Exclusive Alflo rung joint means Twist-Proof performance every time. Exclusive Alflo rung joint means Twist-Proof performance1-3/4 inch slip-resistant Traction-Tred D-rungsHeavy duty extruded rung locks are spring loaded to operate smoothlyMar-resistant end capsSmooth operating pulley with polypropylene ropeHeavy duty modified I-beam side railsDurable shoe rests flat on slip resistant pad or is held in spur position with Shu-Lok feature40 feet size