Hi all!

I'm comparing mountaineering boots and I have a question regarding La Sportivas.

The Evo is 4.2oz heavier than the Cube.

Cube has
"air injected rubber rands"
"INSOLE: 3mm Carbon Tech honeycomb insulation / 4mm EVA"
"MIDSOLE: 3 mm Polyurethane graded for crampon attachment"

Evo has "Insulating Ibi-Thermo 9mm
MIDSOLE: 8-9mm TPU / PU inserts / SBR Aircushion"

I know what a rand is, but what's an air injected rand?
Would y'all please help me understand the differences/technology in the insoles and midsoles?

Thank you!