An innerspring unit is covered with a quilted outer which is a layer of thin organic cotton fabric, a thick layer of organic cotton batting, a thick layer of organically processed wool from organically raised happy sheep, and a layer of our premium European organic cotton fabric all quilted together to prevent shifting. This provides a 6" strong, supportive mattress with a nice even top for safety. 260 coils. This mattress exceeds all the CA and US flame retardancy guidelines without any flame retardant chemicals. Fits all standard cribs 28" x 52". Approximately 6" thick.