The design of the iPhone 6 and iPhone 6 Plus is influenced by that of the iPad Air with a glass front that is curved around the edges of the display, and an aluminum rear that contains two plastic strips for the antenna. The back is built of 6000-series aluminum. Both models come in gold, silver, and "space gray" finishes. The iPhone 6 has a thickness of 6. 9 millimetres (0. 27 in), while the iPhone 6 Plus is 7. 1 mm (0. 28 in) in thickness; both are thinner than the iPhone 5c and iPhone 5s, with the iPhone 6 being Apple's thinnest phone to date. The most significant changes to the iPhone 6 and iPhone 6 Plus are its displays; both branded as "Retina HD Display" and "ion-strengthened", the iPhone 6 display is 4. 7 inches in size with a 16:9 resolution of 1334x750 (326 ppi, minus one row of pixels), while the iPhone 6 Plus includes a 5. 5-inch 1920x1080 (1080p) display (401 PPI). The displays use a multiple-domain LCD panel, dubbed "dual-domain pixels"; the RGB pixels themselves are skewed in pattern, so that every pixel is seen from a different angle. This technique helps improve the viewing angles of the display.