Point (1) The JUMBOs main compartment is over 50% larger than the Fatboy. In addition, it has three zippered accessory pockets, two sleeve pockets, and one drawstring pocket fitted for a 32oz/1L Nalgene water bottle or a radio. The Jumbo has four places for modular expansion with other Maxpedition accessories using Malice clips. External keyper on shoulder strap for gloves and internal silent keyper for keys. We also elected to use a 2 lockable main buckle.
Point (2) The JUMBOs rear slip compartment is now equipped with large loop Velcro patches to accommodate our Hook & Loop Modular Accessories (e.g. #3501 Universal Modular Holster, sold separately). This allows the user to position their concealed carry firearm for a quick strong side draw or weak side cross draw.
In conclusion, you asked for it, we built it.