This papercraft is a Sphere M12 Helmet, a high quality helmet appearing in the first-person shooter survival horror video game series S.T.A.L.K.E.R., the paper model is created by Sinner. It is a separate usable item in the last game in the series.
A high quality, aluminum/titanium combat helmet with cloth camouflage used by Duty and the military, the Sphere-12 is perhaps one of the best available helmets, with slightly higher gunfire protection and psionic protection than its brethren. It comes by default with camouflage (Woodland pattern for military stalkers and urban for Duty). It is normally used as part of a combination that includes PSZ series body armor. Comes with electronics slots.
It is usually worn with a gas mask by stalkers, although variants with a simple faceplate are also common among military stalkers. [Source: wikia]
You can download this papercraft template here: S.T.A.L.K.E.R. - Sphere M12 Helmet Papercraft Free Template Download [Box] [Gavitex]