Therm-a-Rest Prolite Apex Regular Camping Mat - HeatwaveThe self inflating ProLite Apex camping mat achieves unrivalled warmth without adding excess weight to your pack. Featuring a StrataCore construction, a continuous layer of thermal foam is sandwiched between alternating ridges of air and foam to yield the best warmth to weight ratio possible. For personalised sleeping comfort, once inflated top up with a few breaths to increase firmness. Featuring the new WingLock Valve system, it maximises airflow