Werner; Access Ladder; Series Wh, Folding, Heavy Duty; Extension Height: 8.900 -10.300 Ft; Rung Size: 3/4 X 5-1/2 In Actual Lumber, 1 X 6 In Rough Lumber; Material: Wood; Tread: Grooved; Load Capacity: 350 Lb; Rough Opening Width X Length:22-1/2 X 54 In; Rail: 3/4 In X 4-1/2 In Actual Lumber Size, 1 X 5 In Rough Lumber Size; Approx. Ladder Width: 14-1/2 In; Approx. Cu. Ft. Per Unit: 12.300