- Durable Materials: Unlike other mattress foundations, we do not use Engineered Wood, particle board, or MDF. Instead we use 100% Yellow Pine to make our extremely heavy duty foundations. - No Squeaking: We knew that this is a major concern with every foundation, so we designed our mattress foundations in a way that completely eliminates squeaking. - Enhanced Mattress Performance: Perfectly aligned support that will increase both the performance and longevity of any mattress. Four-inch apart slats to insure better mattress breathability.