Hello,
M95 helmet for enlisted personnel of the foot artillery (heavy artillery, fortress artillery, position artillery, siege artillery, then rail-mounted artillery such as "Lange Max" and "Big Bertha," etc.).
This is the Prussian eagle, but the one used by the "old regiments," with an oval FWR (Frederick Wilhelm Rex) instead of FR on the chest. Therefore, it's marked 1, 2, or 3 A.F. for Artillerie zu Fuß (Foot Artillery).