The Beautyrest Triton Foundation provides strong and stable support for all Simmons mattresses. When used with a proper supportive bedframe, the Triton Foundation helps prevent sagging and bowing for the life of the mattress. Constructed of high-grade wood and steel struts, the Triton Foundation features an exclusive center Power Beam to reinforce the span in the middle of the bed. It is available in two models: 9" standard height, or 5.5" low profile height. King and California King mattresses require 2 boxsprings.