After the great success of the RAZR and sibling SLVR series, Motorola defined the standard of a slim phone. The market changed, and every manufacturer had to take the RAZR as an example and develop rival models. The ambitious Koreans from Samsung like to be "world first" and try to always offer the latest technology, so they soon started offering rival models under the Ultra-series branding. That way we saw the world's thinnest phone (X820 Ultra 6.9) at 6.9mm thickness, and the world's slimmest slider with 3-megapixel camera, the D900 Ultra 12.9. In February 2007, Samsung announced the second generation of slim devices, the Ultra II series, which don't really slim the profiles down, but come with upgraded functionality. The X820 is replaced by the Ultra 5.9 U100, and the D900 by the Ultra 10.9 U600. The U600 is very identical to the D900, but the bigger brother U700 Ultra 12.1 is its 3G-capable upgrade, which allows for faster speed of the Internet and video calling feature.