Swix Diamond Stone

Durable and essential for anyone doing tuning at home. Haven’t had any issues with peeling. The quickest and easiest way to remove burrs. A must have for low tide years and anyone who ventures off trail, your rock skis will thank you

If all your ski mountaineering takes place entirely on snow, then you don't need a diamond stone.
However, if your skiing surfaces include occasional interludes of rocks and other non-snow surfaces, this diamond stone is an absolute must for your tuning kit.
Or even if you don't have a tuning kit, this diamond stone will still be hugely helpful all by itself in removing overhanging burrs caused by close encounters of the rock kind.
If you do have a tuning kit, or at least have the ability to sharpen your edges with a metal file, you'll still want to use a diamond stone first to spare excessive wear on your metal file from attempting to remove burrs, plus rock hits can often case harden a metal edge: if your file is suddenly skipping over a section of the metal edge without sharpening it, a few passes back and forth with the diamond stone will magically remove that case hardening effect.