The bag is designed to accommodate one Mark 3 AC and one battery at most, which we've found is about the comfortable limit for one-handed carrying. Note : We don't recommend storing batteries in the bag long-term, as it may trigger over-discharge protection and affect battery performance. Two mesh bags with buckles are included, ideal for storing hoses and adapters. You can attach them to either side or the top of the carry bag for easy access. Tip : You can also use the mesh bag to cover the intake hose. It helps keep bugs (or even frogs!) out. Its straps come with multiple attachment loops, so you can adjust the mesh bag position based on your needs.