What guardrail is recommended for my existing bleacher unit?

A bleacher should have a guardrail along the back and the open ends where the drop is more than 30" to the ground below. The guardrail should be at least 42" high and, if using a vertical picket guardrail, all openings should be small enough that a 4" sphere cannot fit through. If chain link fencing is used, it is recommended using chain link that has a 1.25" (or less) mesh to discourage kids from climbing.