Terms and Condition: Purchase any Serta iComfort or iComfort Hybrid mattress between May 17th and June 5th 2017 and receive either a free standard box spring (same size as mattress purchased) or up to $800 off a qualified Serta adjustable foundation. Savings offers on the adjustable foundation will vary by model and size and are available only with the Motion Perfect III and Motion Custom II adjustable foundation models. Maximum $800 savings applies only to King size Motion Custom II adjustable mattress sets. Offer valid on qualified purchases made in store at Mattress Depot USA store locations while supplies last. Product availability, pricing and offer dates may vary by retail location. Void where prohibited by law.