Learning leads to evolution and we've learned a LOT since the top-rated, best-selling Calor Pant first came on the scene 10 years ago. First off, fabrics have evolved to be tougher while somehow being lighter weight and more comfortable. Crazy we know, but true. Durability was priority number one for the evolution of this lineup as Calor has always been the workhorse of our apparel collection. Added features, including interior knee pad sleeves, leg vents, reinforced knees and an overall improved fit ensure the Calor EVO Pant will continue to be everything you need for those extra rugged, mild to cool weather hunts.