A box spring is a bed base constructed using a sturdy wooden frame base with a heavy flexing steel spring. The purpose of the box spring is to raise the mattress’s height, making it easier to get in and out of bed, to absorb shock and reduce wear to the mattress, and to create a flat and firm structure for the mattress to lie on. Our True Flex box spring provides strong, flexible support moving with the mattress to prolong the life and comfort of your mattress while ensuring you experience support for the life of your bed. With the increasing height of mattresses, you have the option of a “regular profile” box spring 8” in height or the “low profile” box spring at 5-1/2”. Changing the height of the box spring will not affect the support of feel.