The Polish MP4 gas mask is a close copy of the US M17, which was copied by several countries including Poland. Since the MP4 was based on the M17, most of the accessories for the M17 should work with the MP4. Features: Authentic Polish Army Gas Mask Comes With Original Filter Set, Mask, and Carry Bag Large Clear Lenses - Excellent Field of View Speech Diaphragm - Easily Communicate While Wearing Mask Six Point Adjustable Head Straps Shipping $15.00