How much railing does this cover? (How long a run?) Doing 42" high.

Hello, thank you for your question. The item shown is the hardware kit used for our Classic Composite Series railing options with cable rail infill. This kit is used in 36" rail height applications. Hardware kits are available specifically for 42" rail heights. One kit is required for any run of cables up to 60' long while passing through any intermediate posts. Any angle, corner or pitch changes will require the cables to be terminated and started again with a new hardware kit. For more information, please visit https://www.timbertech.com/ -AZEK Customer Care Team.