The Stream GTX is a mid-cut hiking boot featuring 360 degree breathability from the Gore-TexA(R) Surround(TM) Technology and an innovative midsole. Durable abrasion resistant mesh upper provides protection while Nano Cell 2.0 structure provides maximum breathability New Nano Cell 2.0 Technology works with Gore-TexA(R) Surround(TM) aeration channels within the footbed and midsole STB control system inegrates Gore-TexA(R) Surround(TM) ventilation outlets and provides a comfortable, snug fitting, and stable boot VibramA(R) XS Trek with Impact Brake System(TM) sole provides traction and grip Specifications ITEM NUMBER: 24D SIZES: 38 - 47.5 (half sizes) WEIGHT: 14.40 oz (409g) UPPER: Abrasion-resistant mesh / Nano-Cell(TM) 2.0 / PU TechLite toe and heel LINING: Gore-TexA(R) Surround(TM) MIDSOLE: 5mm Ortholite Insole / Compression Molded EVA / TPU inserts / Gore-TexA(R) Surround(TM) aeration channels SOLE: VibramA(R) XS Trek with Impact Brake System(TM) / FrixionA(R) Blue LAST: Tempo2