This is a new never issued Israeli made screw on hydration system drinking tube with integral finger squeeze valve.  Valve opens temporarily when you use a thumb and a finger to squeeze the two loops together, then reseals when released.  Screws on by hand to Israeli gas masks that have the hydration port and nipple tube inside the mask.   Fits Israeli civilian youth, Israeli civilian adult, and Israeli M15 military masks.  Will not fit US gas masks or any other masks that I am aware of.

Note: older Israeli gas masks will not have the hydration port on the mask, so this tube cannot be used unless you have this port.