The B4 SWIFT is often recommended as the ideal VFR flight bag. It's designed to hold one or two full-sized headsets plus a handful of charts, and/or an iPad, plus all the small stuff you'll want along for the ride. It also serves as an unbeatable carry-on personal bag when traveling on commercial flights, or just as a terrific daily bag for a wide variety of personal and professional uses.
The B4 does NOT include a SLIM HANDLE KIT. If you ever think you'd like to remove the CS4 and zip just the two End Caps together to make the B0 SLIM, you'll need to make sure you also order an SLIM HANDLE KIT.
The CS4 provides, that's right, four inches of storage depth, but keep in mind that there is also two thin flat storage areas BETWEEN the three modules. (Remember, it is a soft bag so it can expand slightly in every direction.) Keep in mind also that you can add any other Center Section to the B4 (like zip a CS2 in between the CS4 and the FCR) to add more storage on certain days. Any FLEX System module can zip onto any other FLEX System module. The Main Compartment of the CS4 has locking zipper sliders.
This configuration will very commonly be used to carry two full-sized aviation headsets of any brand. (There is a nice, slightly-tricky way place two large headsets - like the BOSE A20 - inside this space. Just "intertwine" the ear cups in opposite directions. It's really nice to fit two headsets of any kind in such a relatively small space.)
There is a specially-designed pocket on top of the CS4 to hold Sunglasses and their case.
A small collection of charts or flight docs can go in the space between the CS4 and either of the End Caps. A 13" Ultrabook or MacBook Pro can also fit into this "in between" space, and the iPad (or other tablet) can go in the main pocket on the FLAT CAP REAR
The B4 SWIFT also works amazingly well as a daily personal bag and/or as a commercial carry-on bag. A 13" laptop plus a load of documentation plus an iPad, plus all the small stuff like cables, adapters and support stuff for all your technology, your digital camera, snacks, etc - all of this fits easily in this bag. Even your noise-reduction headset for those long flights.
The other great thing about this bag is that it is actually TWO bags for the price of one. Not only is it a B4 SWIFT, but you can also build a B0 SLIM by removing the center section and zipping just the two End Cap modules together. (If you ever think you'd like to remove the CS4 and zip just the two End Caps together to make the B0 SLIM, you'll need to make sure you also order an SLIM HANDLE KIT.)