How do self-inflating camping mats work?

Self-inflating camping mats use compressible foam insulation and inflate like an airbed without requiring the use of an air pump. They are warmer than airbeds, and more packable than simple foam camping mats. They provide a comfortable and portable sleeping surface that can be carried with ease during camping, hiking, or other outdoor activities. It sounds like magic, but there

QPAU Self-inflating Sleeping Mat with a Built-in Pumpfor couples, 5 Inches Ultra-Thick Inflatable Camping Pad, Lightweight and Portable, for Camping,

QPAU Self-inflating Sleeping Mat with a Built-in Pump for couples

The Camp Self-Inflating Mat is a comfortable, durable option for the adventurer who wants a quality pad at an affordable price. Utilizing the

Camp Self-Inflating Sleeping Mat

Double Sleeping Pad for Camping, Ultralight Self Inflating Camping Pad

How do self-inflating camping mats work?

How Do Self-Inflating Sleeping Pads Work?

Self-Inflating Sleeping Pad - Grey - Foxelli

Sleeping pad - Wikipedia

【Extra long & 5 Thick Sleep Support】The self inflating sleeping mat for camping is up to 81*26*5 inches after inflation, bringing you extra thickness

WILSNEY Camping Sleeping Pad, 5 Inch Ultra Thick Self-Inflating Sleeping Mats with Pillow and Built-in Foot Pump, Compact & Lightweight Camping Mat

Double Sleeping Pad for Camping, Ultralight Self Inflating Camping Pad