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 multiple 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.
The Tenkara/Spin/BFS Guide sling differs from the Tenkara Guide Sling in one main respect. The Tenkara Guide Sling has molle webbing and shock cords across the top of the outer pocket. The Tenkara/Spin/BFS Guide sling has a second molle webbing along the bottom of the outer pocket. Two shock cords are fitted on the lower webbing, allowing you to securely hold two of the Long Rod Cases with shock cords top and bottom.
The lower molle webbing and shock cords offer a significant advantage over holding the Long Rod Cases in the external rod sleeves. If a two piece rod is held in the external rod sleeve, it will tower over the top of the sling and catch on branches as you walk down a streamside trail. The shock cords allow you to hold the Long Rod Case with the lower end quite a bit below the bottom of the sling. The top end will not stick out and catch on branches. You may have to remove the sling or rotate it around your body before sitting down, but that is a small price to pay for being able to carry two two-piece rods and not have them catch on branches. Actually, if you sit down to eat lunch, the Long Rod Case will help to turn the ZimmerBuilt Tenkara/Spin/BFS Guide sling into a "table."