Pennwood Unfinished White Oak Solid Hardwood 11/32 in. Thick x 7.5 in. Wide x 48 in. Length Retrofit Riser, $44.99 USD/Box, LL Flooring (Lumber Liquidators)

This White Oak Retrofit Riser is placed on a stair riser's step face, complementing the lower stair tread or hardwood flooring. It is unfinished and measures 11/32 in. thick by 7.5 in. wide, and 48 in. long. Priced at $44.99 USD per box, it can be purchased from LL Flooring (Lumber Liquidators).