I am not sure what you mean...
If you are talking about engineered products that you can buy and then use, then guns and scopes can be bought, as can the other items listed. Few devices are useable by nonengineers, and EZ Thro Dynamite I and II (are there more) can be used by nonengineers.
If you are looking into engineering for its benefits (like what can you make for yourself that are good), then just about everything. All the devices have uses of some sort or another. Not only that, but you can use all the explosives you make.
Anyway, i am sure you get the idea.