Have you ever felt uncomfortable in the summer heat when your backpack contacts your back, preventing sweat from drying? This VAUCLUSE backpack ventilation system is made of high-density polyethylene and creates a forced airflow path between your backpack and your back, drying the sweat you produce. It's gear that has eliminated back discomfort for me during my seven mountain trips. Once you attach it to your backpack, you can head straight to the mountains! Scratches and Stains: It's been used about seven times, so there are some wrinkles and minor scratches, but no noticeable stains. I would like to sell it to mountaineers who understand that it is a used item. The included cable ties (zip ties) that came with the purchase have deteriorated and were discarded, so they are not included this time. Please prepare your own. How to attach it: Search for "瓦奇岳 VAUCLUSE" (Wachidake VAUCLUSE) to find instructions!