Merino wool pieces from any brand are fragile. But I’ve worn the same pair of First Lite Corrugate guide pants for 100+ days of whitetail hunting in Alabama briars and on two week long elk hunts where dead fall snags your pants constantly and tries to rip them off of you and they have 0 holes and look brand new. Sitting in a tree right now wearing the Corrugate Guide jacket I’ve also worn a ton and the new Guide Light pants that came in yesterday, I expect the same outstanding durability for them and they are even more comfortable in warm temps.