510 Bonnell coil with 6 turns 7" height and 14 1/2 gauge wire. 24 Steel edge supports. Strong Flex foam through center third. 8 Oz insulator pad throughout entire mattress, Both sides. 3/4" High density foam topper, Both sides. Triple sewn handles for easy rotation. All natural aloe vera fabric, Both sides. Quilted to 3/8 + 20 Oz dupont holifil.