Arke Nice1 Wood Tread Spiral Staircase Kits - 102-3/4" to 120-1/2" Height - Hi-Gloss BLACK Enamel - Adjustable, Interior Stairway (51" Diameter) Standard kit includes 12 multi-layered birch plywood stair treads, a matching landing, a complete handrail, and all necessary hardware and connectors. The height range for the kit is adjustable from 102-3/4 in. to 120-1/2 in. Powder coat finished painted in Hi-Gloss BLACK. Handrail is an extruded PVC coil. Handrail diameter is 2 in. Can be installed in a clockwise or counterclockwise rotation. Interior installation only. Stair treads and landing are made of multi-layered plywood with a beech wood veneer and a polyurethane protective coating.