The M1 canteen cap allows water to be consumed from a canteen (1-quart or 2-quart) while the user is wearing a protective mask equipped with a drinking tube (M17A1/M17A2/M40/M42).
- "No Unauthorized Hydration Please," PS, The Preventive Maintenance Monthly, January 2012, p. 41. [pdf]
- CAP, WATER CANTEEN, FIELD, 1 QUART AND 2 QUART CANTEENS
- Water canteen cap for use with the M50/M51/M52 series masks: 8465-01-529-9800
- http://www.tecom.marines.mil/Portals/120/Docs/Student Materials/FMST Manual/M40FMST1221.doc