You’ve selected: Economy Fence Rail 16′; 2×6 Nominal Hollow, for use with 2, 3, or 4-rail fences. 

Note: If you’re unsure how many rails to order, follow this guide: 

2-Rail: Order 1 rail per 8′ section.

3-Rail: Order 1.5 Rails per 8′ section and

4-Rail: order 2 rails per 8′ section.