The D1228-2 aluminum 28 ft extension ladder has a duty rating of 225 lb and interlocking side rails. The TRACTION-TRED? 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? feature. Mar-resistant end caps help protect the surface ladder is leaning against. Exclusive ALFLO? rung joint means TWIST-PROOF? performance every time.