This organic innerspring mattress employs traditional Bonnell style coils as a core, topped with layers of felted certified organic wool and then surrounded with a GOTS certified organic cotton fabric quilted to organic wool batting. This is a firm mattress designed for cost effectiveness with less batting than our other innerspring mattresses. Made specifically for kids or adults up to 150 pounds. Approximately 7 inches thick. Designed to be one sided, no need to flip this mattress.