The D1220-2 aluminum 20 ft extension ladder has a duty rating of 225 lb and interlocking side rails. The TRACTION-TRED(R) D-rungs are slip resistant. Spring-loaded locks operate smoothly for easy operation. Shoes rest flat or are held in spur position with SHU-LOK(R) feature. Mar-resistant end caps help protect the surface ladder is leaning against. Exclusive ALFLO(R) rung joint means TWIST-PROOF(R) performance every time.