Drawing on Therm-a-Rest's pressure mapping technology, the Lumbar Pillow features die-cut foam down the center to reduce pressure along the spine, while maintaining density on the sides for the lateral support. It's self-inflating to allow a personalized level of support and can be adjusted with one hand to add critical comfort to bad seats anywhere. Features pressure mapping technology to even out back supportDie-cut center foam reduces pressure for the spinal regionDie-cut foam also maintains side density for reduced horizontal slipping and enhanced lateral back supportSelf-inflating design can be adjusted to customize comfort for each personEasy to pack, use, and adjust with only one hand while sittingWeighs 4 oz (120 g)External Dimensions: 16L x 7W x 2.4H in. (40.64 x 17.78 x 6.1 cm)External Fabric: PolyesterInternal Fabric: Urethane Foam.