BACK TO BACK COMBINATION, METAL FRAMING TYPE; AISI LOW CARBON STEEL MATERIAL; PRE GALVANIZED FINISH; 20 FT; 1-5/8 INCH; 1-5/8 INCH; SOLID CONFIGURATION; 16 GAUGE THICKNESS; COLD FORMED PROCESS; 1.789 LB/FT WEIGHT; 2 CHANNEL(S)