Salomon's Shift Pro series consists of backcountry ski boots built to accept standard tech or AT bindings as well as Salomon's newer Shift Bindings that require tech setups for uphill travel and AT setups for downhill. The Shift Pro 90 AT Touring Boot is the comfiest option in that series. Its 90 flex feels forgiving for lighter skiers and beginners learning to backcountry tour. Both the Custom Shell HD and My Custom Fit 3D liner are thermo-moldable so boot-fitters can fit the boot to your foot's shape for a customized feel. The Shift Pro also features a low-profile Surelock walk mechanism that goes in and out of ski mode with the flip of a switch.