Products > Climbing-Equipment > Extension Ladders > 3500-AT Series > 3524-AT 24ft Type II Aluminum D-Rung All Terrain Extension Ladder > 3524-AT

3524-AT Extension Ladders - Keller US
3524-AT Extension Ladders - Keller US
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3524-AT 24ft Type II Aluminum D-Rung All Terrain Extension Ladder


SizeStyleMax. Safe Working HeightReach HeightLoad Capacity
24ftMulti Section21ft23ft225lb Load Capacity Commercial Use

The 3524-AT All Terrain aluminum extension ladder eliminates uneven ground with the factory installed adjustable leveling system. This system precisely adjusts in 3/8in increments up to 8-1/4 in, making it easy to use. The dual action feet on the ladder are for use on hard or penetrable surfaces and swivel easily.  D-rungs are slip resistant. The ladder has a duty rating of 225 pounds making it durable, long lasting and able to meet the demands of the job. The exclusive 3-piece rung-to-rail connection means a twist-proof performance every time, and the lightweight aluminum makes it easy to transport.


  • Factory installed adjustable leveling system exceeds OSHA and ANSI requirements
  • Easily adjustable in 3/8in increments up to 8-1/4in
  • Exclusive 3-piece rung-to-rail connection means twist-proof performance
  • 1-1/2in slip-resistant D-rung steps
  • Durable extruded rung locks are spring loaded to operate smoothly
  • Convenient built-in bubble level
  • Heavy duty modified I-beam side rails
  • Dual action foot for use on hard or penetrable surfaces
  • Durable shoe rests flat on slip resistent pad orin spur position for use on hard or penetrable surfaces
  • Mar-resistant end caps


FeatureSize / Details
Max. Safe Working Height21ft
Max. Open Extended Length21ft
StyleMulti Section
Load Capacity225lb Load Capacity Commercial Use
Duty RatingType II Duty Rating
Approx. Closed Length150in
Approx. Cu. Ft. Per Unit8.3
Approx. Product Weight (lb)38.2
Approx. Shipping Weight (lb)38.2
Base Width20in
CertificationsANSI A14.2 (2007), OSHA
Flange Dimension15/16in
Max. Load225lb
Number of Sections2
Reach Height23ft
Section x Rungs2 x 12
Rails Dimension3in
Rung Dimension15-1/4in x 1-1/2in
Rung TypeD-Rung

Package Contents

Part NumberQtyDescription



Additional 3500-AT Series Models

Model No.SizeMax. Safe Working HeightMax. Open Extended LengthApprox. Closed LengthApprox. Cu. Ft. Per UnitApprox. Product Weight (lb)

Different types of ladders are designed to keep you safe and productive when climbing or standing. Using the wrong style of ladder or simply ignoring the limitations of climbing equipment can result in a fall or serious injury.
Height reach Height is referring to the actual ladder height. Extension ladders should be 7 to 10 feet longer than the highest support or contact point, which may be the wall or roof line. The highest standing level is four rungs down from the top. The highest permitted standing level on a stepladder is two steps down from the top.

Reach height is the maximum reach assuming a 5’6” person with a vertical 12” reach.
Ladders are designed to safely hold up to a specific amount of weight. The Werner Performance System defines five different capacities using a color and star rating system. The Duty Rating is defined as the maximum safe load capacity of the ladder. A person’s fully clothed weight plus the weight of any tools and materials that are carried onto the ladder must be less than the load capacity.

Performance system
Werner offers ladder made from fiberglass and aluminum. Each material has characteristics which make it best for certain applications, or one material may simply fit the personal preferences of the user. For example, if working around electricity users should select fiberglass products due to their non-conductive side rails.