right, light weight with stable stiffness at a wide range of temps was the appeal of Pebax touring boots, downside, is difficult to punch and hold the punched out shape, now with newer plastics I see Pebax used mainly in cuffs.boots use our True Flex PU, which maintains its flex characteristics across a wide range of temperatures (think -20°C/-4°F to 20°C/68°F). This means that the boot doesn't get overly soft in warm conditions nor incredibly stiff in cold conditions. However, this consistent flex in both warm and cold conditions comes with a trade off - the plastic is stiffer at room temperature and a little harder to put on vs. a regular PU boot.
as do my Tecnica Zero G touring boots-
The Speedmachines have a different plastic on one side of the lower clog's instep area and this helps.