During your act you remove your flask and pour yourself a shot. The audience can see that ever last drop pours out.Later in your act you pour yourself another drink and another shot comes out. You can do this 8 or 9 times. Each time it appears as if there is no more liquid in the container but somehow it just keeps refilling itself. This is a greatcomedy item. Made of brass and plated in chrome. Audiences love this.
Craftsmanship is mediocre. You have to handle it carefully to mask obvious gurgling. But worst of all, the cap is worthless. It does not screw on and doesn't fit snugly. If you want to carry the product in a pocket, you need to get a cork. There are reports of flaking, so you wouldn't want to drink out of it. - Harry Mossman