Prior to the official unveiling of the iPhone 4 on June 7, 2010, two prototypes were brought to mainstream media, breaching Apple's normally secretive development process. Many of the speculations regarding technical specifications proved accurate.
The iPhone 4 is structured around a stainless steel frame which both acts as the primary structure for the device, and additionally acts as the iPhone 4's antennae. The stainless steel enclosure features three slits that divide the band into three sections; the left section of band acts as the Bluetooth, Wi-Fi, and GPS antenna, and the right and lower bands sections act as the antenna for GSM and UMTS connectivity. There is some debate as to whether or not this causes issues with signal strength and availability. The act of touching the gap between the two antennas with an un-gloved hand potentially bridges these two separate antennas, leading to poor signal reception.