USGI Chemical-Biological Mask External Drink Tube (M40, M42, MCU-2/P)

US Genuine Issue External Drink Tube for M40, M42, MCU-2/P chemical and biological (CBRN) masks - new, unissued, and in original packaging! A specific length of specialized tubing designed to provide an airtight connection between a canteen and the internal hydration port of a gas mask. 

It is officially classified as a critical safety component for chemical and biological defense, meaning its manufacturing and testing standards are strictly regulated to ensure no toxic agents can bypass the tube's seal during use.

NSN

• 4240-01-286-1841

Features

• Leakage Prevention: Specially tested to ensure no leakage under positive pressure (up to 3.0 inches), preserving the vacuum seal of the mask against toxic agents.
• Quick-Disconnect Coupling (QDC): Features a self-sealing, quick-disconnect coupling half that allows for rapid attachment and detachment from a canteen cap.
• Hydration Compatibility: Designed to plug directly into the M1 NBC Canteen Cap (standard 1 and 2-quart GI canteens), enabling "hands-free" drinking without mask removal.
• Tube Dimensions: The drinking tube is approximately 3.56 inches in overall length with an outer diameter of 0.29 inches.
• Dual-Tube System: Works as the external half of a system that includes an internal drinking straw; the external tube delivers water to the mask port, while the internal straw allows the user to sip.
• Material: Manufactured using specialized rubber compounds resistant to chemical, biological, radiological, and nuclear (CBRN) contaminants.
• High-Flow Design: Engineered for a high flow rate to reduce the effort required for hydration during extended missions.
• Durability: Built to withstand harsh field conditions, featuring resistance to cracks and cuts that would otherwise compromise the respirator system.
• Commonly Used With (Masks): This specific NSN is the standard replacement part for the following gear: M40, M40A1, M42, M42A1/A2, MCU-2/P, MCU-2A/P, and Millennium series.
• Commonly Used With (Canteen Caps): Standard M1/NBC caps.