Thermarest's latest innovation aims to make inflating a mat easier but we're not sure it's worth the pay off in extra weight and pack size. At the head of the mat you'll find a wide opening with a neoprene flappy inner and a dry bag style buckle closure. The principle is that as you gently blow air into the mat it also sucks atmospheric air in thus requiring less input from you to get it to inflate. This takes a bit of practice and requires just the right angle and amount of air, once you've got the hang of it the mat definitely inflates quicker than if you were blowing directly into a valve. Deflation happens quickly, especially if you're lying on the mat at the time, unclip the buckle and the mat collapses on the floor in a split second. All this being said we still prefer to use an Exped style Shnozzel bag.
The airframe structure of the mat is borrowed from the Evolite, a supremely comfortable mat which combines alternating sections of foam and air. The Trail King is equally as comfortable as the Evolite and at 6.3cm is sumptuously thick, which helps to iron out any unevenness in the ground. A low r value of 1.8 restricts usage to 2 seasons.
We don't think that the Trail King justifies its bulky and cumbersome weight and pack size, at 830g and a rather chunky 28 x 17cm. This will take up a lot of precious litres in a backpack so chalk this one up as a car camping only mat.
Unless you’re sold on the Speed Valve system we would recommend checking out the Evolite which is lighter, has a smaller pack size and has a higher r value as well as being about £20 cheaper.
