This is the "REVOLUTIV VEST 3L" hydration vest from RAIDLIGHT. It has a capacity of 3 liters. It is very lightweight, weighing approximately 70g. It is suitable for trail running with minimal gear, such as short races. There is a stretch pocket on the back that can store a compact windbreaker or rainwear. (Quoted) I purchased this but have kept it stored at home without using it. I am selling it to organize my belongings. I plan to waterproof it and pack and ship it via Yu-Packet Post. I may change the shipping method, but I appreciate your understanding that this item has been stored at home. #running vest #trail running #mountaineering #outdoor #trekking #trail running backpack