The different ski binding manufacturers have different binding angles so changing from one brand to another can affect your stance, posture & balance etc.The measurement is the additional height of the heel above the toe.
0mm (with alpine boots)
|Marker Duke/Baron/Tour||+6mm (with AT boots)|
|Look/Rossi Pivot/FKS||+5mm (only flat with their 5mm toe shims)|
|Dynafit Radical Speed/ST/FT||+15mm (with Vulcan/Mercury boot)|
|Dynafit Radical ST/FT||+12mm (with Tecnica Cochise boot)|
|Dynafit Beast 16||
+6mm (with Vulcan/Mercury boot)
When I had my boots correctly aligned & balanced by Colin & Andi at Solutions4feet (see the UK Boot Fitting & Alignment section) I balanced best with my toes 2mm higher than my heels. I therefore use 7mm shims under my toe bindings to offsets the +5mm delta of the Vist heel piece, as shown in the pic.