Bubble Head HatIt really pops. The Immersion Research x Territory Run Co Bubble Head Hat is a breathable and quick drying five panel hat designed with the outdoors in mind. A crushable brim allows it to be thrown in a bag or pocket while retaining its shape. Breathable mesh side panels keep you cool even when things start to heat up. All day comfort, whether it's under a helmet, on a big trail run, a long uphill skin, or out on the town.