Dominoes spots from one to six are generally arranged as they are on six-sided dice, but because blank ends having no spots are used, seven faces are possible, allowing 28 unique pieces in a double-six set. However, this is a relatively small number especially when playing with more than four people, so many domino sets are "extended" by introducing ends with greater numbers of spots, which increases the number of unique combinations of ends and thus of pieces. Each progressively larger set increases the maximum number of pips on an end by three, so the common extended sets are double-nine, double-12,
Daimler Double-Six sleeve-valve V12 of Motor Sport recounted how Double-Six models could develop violent front axle "wheel wobble" which could only be overcome by stopping the car. Bodies were all mounted after the Daimler pattern on a separate frame flexibly held. A contemporary press report remarked that "when the Double-Six arrives at the door there is no obvious pomp and circumstance. Here is a car that looks clean-cut and aristocratic in its speckless grey paintwork. It is not until one comes close to the car that its great size is realised. The Daimler bonnet is nearly level with the chin of the observer." "Autocar"