The PENTAX Q features Q mount, with a mount diameter shortened to Approx. two-thirds of that of the conventional K mount. This was made possible by reducing the flange back (the distance from the lens mount surface to the image sensor surface) to nearly one-fifth of that of the K mount, as well as by optimizing the size of image circle of its lenses to be proportioned to the size of the compact image sensor. The Q mount system also eliminates an optical finder, mirror box, focusing plate & AF sensor, making the PENTAX Qs body the smallest & lightest in its class. The body has been made from magnesium-alloy, which gives an elegant, high-quality texture to the compact, lightweight camera body while improving its durability.