Comparison : Item # 6061-T6C-300-1410-170, Aluminum Structural Channels American Standard
Item # 6061-T6C-300-1498-258, Aluminum Structural Channels American Standard
Item # 6061-T6C-300-1596-356, Aluminum Structural Channels American Standard
Item # 6061-T6C-400-1580-180, Aluminum Structural Channels American Standard
Item # 6061-T6C-400-1647-247, Aluminum Structural Channels American Standard