Raider blastmaster helmet

Raider Blastmaster Helmet is the headwear component of Raider Blastmaster Armor.

Comprised of a Fireman's Helmet worn on top of a Gas Mask and possibly a fire-retardant covering, the Blastmaster Helmet confers a small (+5) bonus to your Big Guns and Explosives Skills.

Locations
This helmet is an easy find if you go to one of the many raider camps near Vault 101, specifically the Super Duper Mart and the Springvale Elementary (although if you are on hard mode you might want to wait awhile before going to these locations). As with all small and lightweight weapons and armor is a good idea to hold onto as many of these as possible for repairs out on the wasteland. (You can wear glasses with this helmet.)

Pyro Helmet
A cut version of this helmet called Pyro Helmet can be found in the game files of Fallout 3. It is identical from the standard helmet except for the missing bonuses.

Trivia
A "blastmaster" is a common slang word for the demolition and explosives expert in a mine.