The Exped SIM Ultra 3.8 M is a self-inflating sleeping mat designed to add comfort and insulation on outdoor adventures. At 3.8 cm thickness, it offers a cushioned layer between you and the ground, whether you’re camping in mild or cool conditions.

Built with a 20 D recycled polyester shell laminated with TPU film, the mat resists moisture damage and meets Oeko-Tex 100 standards for low chemical content. Inside, 13 kg/m³ PU foam provides consistent padding, and the mat compresses down to a 27 × 15 cm package, making it easy to tuck into a backpack. Weighing 0.61 kg, it falls into the light category of self-inflating pads, balancing low bulk with reliable comfort for multi-day treks.

The R-value of 3.7 measures how well the mat insulates, indicating it helps retain body heat on three-season trips. A higher R-value means better thermal protection, so you’ll stay warmer than on a basic foam pad in cool conditions.