Hiccup's Flight Helmet

Hiccup Horrendous Haddock III wears a helmet that covers his face while flying to protect his face from fast winds (as he flies a Night Fury, the fastest dragon), and as insulation while high up in the sky.

How to Train Your Dragon 2
The top is black with three rows of small spines on the top. There is also the same dragon symbol on his chest that is on both sides. The bottom have is made out of brown leather that covers his mouth. The lower half can come up like a visor. Hiccup usually wears it while flying.

After encountering a mysterious dragon rider, Hiccup is abducted while Toothless falls into the ocean. When a group of Seashockers drag the Night Fury under, Hiccup's helmet is left floating in the water. Stoick and Gobber later finds it while searching for Hiccup. Worried his son might be in danger, Stoick has his dragon Skullcrusher find Hiccup by following his scent from the helmet. Stoick gives it back to Hiccup once he finds him.

Trivia

 * Hiccup's Flight Helemt, as well as his Flightsuit in the sequel, may be loosely based off Toothless.
 * Hiccup's new helmet also includes a Deadly Nadder symbol painted on the top-left side of the helmet's forehead. This is implied to be another nod to his girlfriend Astrid.