The Mammut T Aenergy GTX is a light, durable boot, with a very comfortable fit. It is supported by the high-quality materials 2 Tone PA, Hybrid Shell, Liquid Rubber Protection, EVA wedge with integrated Mammut Rolling Concept & the patented Base Fit lacing system. Also featuring individually cushioning memo foam, the scale-like arrangement of the vibram Scale sole, protective rubber tips & the functional GORE-TEX Performance Comfort Footwear Membrane. Features Base Fit Rolling Concept Memo Foam Hybrid Shell Rubber toe cap Soft Shell 3-D Textile Scale Technology Board lasted Flex Index: A8 Optimally suitable for; Backpacking, Walking Suitable for; Travel, Mountain Hiking