Not only is it the lightest lid on the market at 5.82 ounces (that’s 1.8 ounces more than an iPhone 5), it is also unique in design—and look. The Sirocco utilizes expanded polypropylene (EPP) foam instead of the standard expanded polystyrene. EPP is the same foam used in car bumpers, and it is more spongy and flexible—instead of cracking like EPS, it is intended to absorb the impact without damage. This means it doesn’t need a plastic shell to house the foam. Testers raved about “not really feeling it” on their heads, and the narrow but numerous vents allowed for maximum airflow without the worry of a pebble getting through. Trad and ice climbers in Eldorado Canyon and Vermont both agreed that the magnetic chin buckle was perfect for one-handed use. Ding: One tester accidentally unhooked the buckle by looking down and catching it on his fully zipped jacket.