Small bindings are designed for smaller adult boots—typically US Men's 6-8 or Women's 7-9. This size is the go-to for small-footed men and average-footed women. Getting the right size matters because your boot needs to sit snugly in the heel cup and line up properly with the ankle straps for secure, responsive control on the hill.
If your binding is too big, your boot shifts around and you lose edge-to-edge precision. Too small, and the straps won't reach or your boot overhangs the baseplate, which can cause toe drag. Small bindings solve this for boots in that range by keeping everything aligned and locked in.
One key tip: always check the specific brand's size chart before buying. Sizing ranges vary between manufacturers, and some split their small/medium ranges differently. Also, if you run a bulky boot with thick soles, you may want to size up even if your foot measurement lands in the small range.