Standard Features: 4, 5, 8, 10, and 15 Row Units, 8" Rise/24" Tread, 10" Seat Plank, 17” Front Row Seat Height, Available in 21', 27', and 33' Lengths, Aluminium Frame, Double Foot-boards and Risers on ALL Rows, Chain Link Guardrail, Aisle With Handrails.