Check out this Czech gas mask kit from Budk. This is a full kit with filters and a carrying case. The M10M is a cool conversation piece or also great for a bug-out kit.
Another product in the tool / Weapon category is the United Cutlery M48 Tomahawk Survival Tool. The below video demonstrates the multiple uses of this tool. This is a great tool to be used for many different situations, Camping, Survival, Hunting, Zombie Smashing, and just plain target practice. I even hear Ninja will use them from time to time. And it’s only $40 on Amazon. United Cutlery UC2765 M48 Hawk Axe with Nylon Sheath
The BioLite wood burning stove is a cool portable camping tool that allows the user to use wood as fuel rather than propane. There is also a thermoelectric electric generator that converts heat from the fire into electricity. The system can operate at 5v from 2 to 4 watts of power via a USB connector.
BioLite sells this product for $129.