M5-11-7 Assault Gas Mask
The U.S. Army M5-11-7 assault gas mask was a modified version of the M3 lightweight service gas mask. The M5 gas mask was susceptible to cold weather because of the use of neoprene, which tended to stiffen the mask and make it difficult for a soldier to achieve a proper fit.
For Operation Overlord, the M5 gas mask was carried inside of the M7 gas mask bag along with an extra gas detection brassard. Only soldiers participating in the initial assault waves were issued the M5 gas mask. Follow-up waves carried the bulkier M3 gas mask in a standard, non-waterproof canvas bag.
Notes
The M5-11-7 assault gas mask is never seen in Saving Private Ryan.