We cut out some foam from the rectangle mats and reserve the major part of foam for lightest and most compact mattresses. We make sure the mattresses have enough room for users' hips and thighs.   Feng Yi outdoor Leisure Equipment Enterprise Co., Ltd. 275, Ke Liao Road, Lung Jin Village, Lung Ching Hsiang, Taichung County Tel:886-4-26380697 Fax:886-4-26380879 Website:http://www.fengyi.com.tw E-mail Box: cindy.fy@msa.hinet.net