Regarding the toe bar options, one important thing to know is that the Supershell is higher than our classic bindings so the SuperShell front toe bar is higher too. Meaning you can't swap toe bars with a classic binding.
Now about the Supershell toe bar options, the carbon toe cup has been designed to make this area more aerodynamic, but we do offer a double toe bar option because this is what we offered in the past and some skiers do not like to change. But if you're looking for the last design, it's the carbon toe cup. The price is the same for both options.