K4S boots for sale, excellent condition. Only wear is very slight rounding of the soles at the toes.
The K4S model is actually lighter and warmer than the Nepal Extreme - see NE Climbs Review . They're also lighter than the Nepal Extreme Evos in the same size!
For Tech info see this Mtn Tools listing .
The previous owner was Cullan Lester, who said these boots kept his feet warm to -20 in Alaska. See an example climb here .
$150 includes shipping within the lower 48.