It’s called the Ventrix hoodie because the insulation is perforated for dynamic venting. The fabric is lightweight and extra permeable. There are underarm gussets for extra mobility in the arms and no shoulder seams to make wearing a pack more comfortable. If you’re going to be sweating and moving around a lot, this is a great option for you. The nylon woven ripstop is water repellent and there’s elastane in the lining. Wear this as a protective outer layer, or put a fleece underneath for super cold temperatures.