The main part of the pack is 19.5"x10"x3" and the second layer (Zimmer calls it the outer pocket) adds another 13"x9"x1.5". The Sling Pack has a small cuben fiber pouch in the main part of the pack and a mesh pouch in the outer pocket. The 2 external rod sleeves will hold 6 tenkara rods, even more keiryu rods or enough sieryu rods for a whole cub scout troup. The external rod sleeves can also double as pockets when you don't need to carry 4 rods. The shoulder strap has molle webbing to attach a Tenkara Chest Pack, Strap Pack or Micro Pack. The Tenkara Guide Sling weighs 10.25 oz. The zippers are water resistant.