Giro, E2 Race Helmet All Mountain Bikes >>> Mountain Bikes by Giro More details and ordering info. When you're out riding, you don't want to be caught without a sturdy brain bucket at the wrong time. No other helmet looks, or performs like this one. At just 10 ounces, and with 24 vents, the E2 is as lightweight and well ventilated as it gets. You'll hardly know you're wearing it, except when you perform that perfect swan-dive over the handlebars. User input on E2 Race Helmet by Giro: Be the first to submit input on this product Submit Input: Your Name: Write or Paste Input here: Upload picture:      Review Guidelines