It is remiscent of a top hat, except that it’s made out of aluminum or stainless steel.
They are designed to make a single-serving of coffee at a time, so if you’re envisioning make Vietnamese-style coffees for several people a crowd, you’ll need several filters. They are quite inexpensive, though, selling for only around $4.00 US each in North America (as of 2007.) The coffee maker is placed on top of a glass, with the brewed coffee dripping down into the glass.
A saucer on the bottom of the coffee press holds it in place on the cup or glass. The sauce is mesh in the centre, to act as a filter. The saucer is attached to tall, solid sides, open at the top (occasionally, these may be two separate pieces.) You put ground coffee in, then insert the plunger. The plunger is all metal. It consists of a perforated disk, attached to a metal handle that has a part at the top that turns. You turn that top part to tighten the plunger. The more you tighten it, the slower the water will flow, and the stronger your brew. After tightening it for the strength of coffee you wish, shake the whole press a bit to distribute the coffee evenly, then put back on top of your cup or glass.
Now you start to pour the hot water in. Some people like to fill it 1/4 full first, wait till all that has flowed through, loosen the plunger by a few turns, then top up with boiling water and let it drip again. While it is brewing, there is a top you can put on to stop the heat and aroma from dissipating.