The D1520-2 aluminum extension ladder has a duty rating of 300 lbs. and have extra heavy duty I-beam side rails. The base and fly sections separate easily and can be used separately. Guide brackets help to ease operation when raising and lowering the fly section. The exclusive ALFLO rung joint means TWIST-PROOF performance every time. TRACTION-TRED D rungs are slip resistant, and the rugged shoes rest flat or are held in spur position with the SHU-LOK feature. Rugged spring-loaded locks operate smoothly. Mar-resistant end caps protect the surface ladder is resting against.