East German Reservists type krug in good condition. Vigilant and combat ready is roughly what it translates to. This looks like it is a 0,5L krug, but it lacks a capacity marking so it might have been more of a display piece.
This is a krug, not a stein. Stein is what English speakers and tourists say. In German a stein is a stone. This is a beverage container, not a rock!
More East German items here.