With cutting edge Triangular Core Matrix construction and ThermaCapture technology, the full-rectangular shaped XTherm NXT MAX delivers a 7.3 R-value while weighing just 680 g (24 oz) in the Large size. Put another way, the best warmth-to-weight ratio of any rectangular sleeping pad ever created. It's warmer and thicker than the previous model, which is why the XTherm NXT MAX cements the legacy of being the go-to rectangular sleeping pad for alpinists, mountaineers and extreme cold expeditions. At 3-inches thick, with horizontal baffles and the added sleep surface of the rectangular shape, all-night comfort and support are at hand, while 70D nylon on the bottom ensures the XTherm NXT MAX holds up to extended expedition use. The WingLock Valve allows for rapid inflation and deflation but is also intuitive and easy to use in frigid weather when the gloves are not coming off. When you absolutely need to be warm no matter the weather, want plenty of sleep surface but space in the pack is at a premium, there is no finer sleeping pad than the XTherm NXT MAX.