Question about supercharger blower boots "direct driver"

[ultra414]

i just bought supercharger blower boots nordica made

though i have not skied with the boots they seem nice

and they has some special technology

there is flexible plastic piece atteched on cuff

so.. i am curious what these small plastic piece do on boot. and

how install them when wearing boot..

 

[JayDope]

take it off to make the boot softer, add it for stiffness