Zappos.com is proud to offer the Avia - A5638M (Metallic Steel Grey/Royal Blue/Yellow Glow/Black) - Footwear: Set out to claim the mountain top in the ready-to-run-wild A5648M trail runners from Avia. ; Breathable mesh upper. ; Durable leather and synthetic leather overlays provide structural support. ; Lightly padded tongue and collar. ; Contoured heel cut for added comfort. ; Removable molded EVA insole supplies soft underfoot support. ; Molded EVA midsole provides durable cushioning. ; Shear Gel-Ryd II heel unit helps absorb impacting shock. ; Cantilever technology helps stabilize the heel and provide increased energy return. ; Solid rubber outsole is designed specifically for the trail, and provides lasting grip and traction over varied terrain. ; Flex grooves allow for more natural foot movement. ; Weight: 14 oz ; Product measurements were taken using size 12. Please note that measurements may vary by size.