HAG was the direct successor to the Ludvig von Bremen Company. The HAG abbreviation stands for Hanseatische Apperatebou Gesellschaft.

This helmet is of the 12 bolt design with four brales or straps to secure the corselet to the suit.
On the divers right hand side is the German design spitcock. Notice the absence of a lifting handle.

Side view showing the air exhaust valve and rear view showing the air inlet connection with non return valve and telephone blanking plug.

Later The HAG company became the HAGENUK Company.