To be fair, machines that claim to brew at 8, 12, or 15 bar are a little off the mark.
They all use Ulka vibration pumps which all deliver a bar pressure somewhere between 8 and 12 bar.
* a 1 to 1.25 ounce coffee beverage
* prepared using 7 to 9 grams of ground coffee
* brewed with clean water at a temperature between 192 and 198 deg F (88-92 deg C)
* brewed with water forced through the grinds at approximately 9-10 atmospheres of pressure (approximately 9 bars of pressure)
* brewed with a coffee grind and tamp such that the brewing flow time is approximately 20-25 seconds