Tesla Men's Ultra Lightweight Running Shoes L510 PR2 For a more comfortable fit or with socks : We strongly recommend ordering half a size up. Tighter fit or with barefeet : Order size as usual (Shoes will loosen up after wearing for a few hours) 5.5 oz Ultralight (tested with size 7 on each foot) : Extremely lightweight design provides actual feelings of being barefooted for a more comfortable and natural walk. Quick-dry function : Integrated vent-mesh upper design maximizes the surface area and keeps your foot cool. Flexible movement- Flex groove sole and Hydro-grip outsole for more traction and stability for all surfaces and terrains.