Sea To Summit Don'T Claim To Have Re-Invented The Self-Inflating Camp Mat, They'Ve Just Taken The Basic Self-Inflating Concept And Added Their Own Touch Of Expertise To Create A Reliable Range Of Mats, And The Camp Mat Si Is The Durable All-Rounder In The Range. A Robust 75D Polyester Exterior Protects A Pu Foam Core That Has Delta Core-V Cut With Variable Core Sizes That Provide More Warmth In The Body Contact Areas And Less Where It Is Not Needed To Keep Weight Down. Also Featuring The Sea To Summit Multi-Functional, High Flow Rate Valve For Easy Inflation, Deflation And Fine Tuning Of The Mat Pressure. This Valve Also Enables The Use Of Sea To Summit'S Jetstream Or Airstream Pumps For Easy Inflation Of Your Mat. Sea To Summit Camp Mat Self Inflatable Mat [Mat Size: Large]