Premium quality, cast brass floor plates are machined for a high quality fit and finish. Hinged for easy use. Subfloor excavation and hardwood floor routing required for installation in existing floors. Sockets allow floating floor to expand and contract with changes in humidity. Requires two per system. Made in the USA. CAUTION! Floor sockets are difficult and often impossible to install on floors with basements or other hollow cavities below, consult an experienced installer for assistance.