The Therm-a-Rest Pro Lite Plus Mattress is Therm-a-Rest s warmest self-inflating pad that uses diagonal-cut foam to increase compressibility & reduce weight making it an excellent choice of comfortable warm & robust mat for backpacking ski touring cold weather expeditions & winter camping The Thermarest Pro Lite has a thick diagonal-cut expanding foam core to deliver four season warmth while remaining lightweight & incredibly compressible for easy packing This self-inflating mat is very simple & reliable to inflate simply twist the valve & let it inflate while you set up your camp You can then top up with a few breaths to personalise the firmness for a great night s sleep The Pro Lite Plus is slightly thicker than the standard Thermarest Prolite it is also warmer & a little heavier making it ideal for when extra insulation & comfort is most important factor for your next outdoors adventure