The Type 1AA is the top of the line model in the Little Giant Ladder lineup, introduced in the fall of 2001. It meets the new OSHA 375lb, Extra Heavy Duty Industrial Rating for ladders. Based on the original Type 1A Little Giant, the Type 1AA uses thicker gauge aluminum and extra bracing to achieve the increased workload capacity. This is an incredibly tough ladder! The Type 1AA is an excellent choice for heavy duty industrial use, construction work, or for the demanding homeowner seeking an incredibly tough ladder. It comes with a Lifetime Warranty (6 year warranty for ladders purchased prior to 2004). Type 1AA ladders make up approximately 15% of Little Giant Ladder sales. The Type 1A is the “Original” Little Giant Ladder, having been in production since 1972. This is the exact model “as seen on tv!” It meets the OSHA Type 1A 300lb, Extra Heavy Duty Rating for ladders. The Type 1A “Original” is engineered to be a rugged ladder; built for incredible durability and maximum weight limit