Pros: Two doses in one unit, much cheaper option than the Epi-Pen.
Cons: Have to train two techniques.
"The Twinject is two Epi-Pens in one, and since you have to carry a couple, it reduces your weight by half. The only issue is that the second dose is essentially given by syringe, so you have to train two techniques (using the auto-injector and giving an SQ injection). The cost alone would justify the training, you can also buy in a twin-pack with a trainer."