Famous Duo-Safety Rail Construction provides the advantage of extra strength without cumbersome weight. Ideal for pumper use - these outstanding ladders have been proven and approved for many years by fire departments everywhere. Installed with standard 3/4" hooks or heavy duty 7/8" hooks for an additional fee. Series 875-A: Channel Rail Construction 750 lb Duty Rated Prong Feet as Standard Rubber Safety Shoes Optional for Hard Surface Use Series 875-A Roof Specifications: Size Closed Length Width Rail Size Weight* 16' 16' 2.5" 19" 3.25" 39 lbs 18' 18' 2.5" 19" 3.25" 44 lbs 20' 20' 2.5" 19" 3.25" 48 lbs All dimensions listed are N.F.P.A. Design Verification Standards. Variations occur in each product of approximately +/- .125" due to the type of rivets, nuts, bolts etc. used. * Weight listed is actual weight of product only.