Salewa Diadem 3-Season Mat - The Diadem 3-Season is a comfortable, versatile, self-inflating sleeping pad with a small pack size, which we developed specifically for use in alpine trekking, hiking and travelling. It is 183 cm long and 51 cm wide. With a thickness of 2.5 cm and a weight of only 495 g, it has an insulation performance with an R value of 2.4.