4′ 8″ To 8′ 4″, 15 Gauge Adjustable Jack Post, Max Ext Load 9,100 LBS, Min Ext Load 18,000 LBS, Additional Support For Crawl Spaces, Attic, Staircase Or Decks, Adjusts With 3/4″ Wrench, O.D. Gauge & Tube Dim 2-1/4″ x 15 Gauge x 49″, Screw Size 1″ x 7″, -5 Thread Support, Collar Size 2-1/4″ x 1/2″, Support Pins 1/2″ x 3″, 13 Gauge Plate Size 4″ x 5″, Corrosion Resistant Inside & Out, Double Carriage Bolt & Nut (Zinc Coated) For Added Safety, Heavy Plates Suited For Wood & Steel, Deep Dish Self-Centering Plates.