Yep, Giro and Bell are the same company.

And ditto indysteel about the certification company.

I have two helmets. My original one is a Bell Alchera in dark grey because it fit well. It looked HUGE on my head though, so I bought another helmet that looks better and is white (more visible). The new helmet is a Giant Ares and it fits differently (works better with a pony tail and is cooler than my other helmet).

So now my old helmet is my winter helmet (it fits layers underneath it better) and my new helmet is my summer helmet.