Amazon's maiden smartphone, which includes four cameras that track a user's head movements to enable special screen effects, ships this week to customers in the United States and is powered by a Qualcomm quad-core Snapdragon 800 processor.

The USD 600-plus device thrusts Amazon into a fiercely competitive smartphone market dominated by Apple and devices running Google's Android software.

It also feeds into Amazon's core retail business. It touts a "Firefly" feature that can recognize objects and direct users to the same item on Amazon's online store.

Dismantling a just-delivered Fire handset, iFixit said on its blog that it discovered radio frequency, power amplifier, audio and Wi-Fi chips also from US chipmaker Qualcomm.

Apart from the quartet of head-tracking cameras, the phone also includes a 13-megapixel rear-facing camera and a 2.1-megapixel front-facing camera.

The device opened by iFixit included 32 gigabytes of NAND memory chips made by Samsung for storing pictures, music and other media. The phone, which has a 4.7 inch LCD display, included 2 gigabytes of DRAM memory from Samsung.

Manufacturers of mobile hardware often employ more than one supplier for memory chips and other components in their devices.

The handset included a near field communication chip, enabling features such as mobile payments, from NXP, according to iFixit.

The Fire smartphone also employs a touchscreen controller from Synaptics, and a communications chip from Skyworks.

The "Fire" is priced at USD649 contract-free or USD199.99 with a contract with AT&T — in the same neighborhood as the iPhone. The price is a departure from the e-commerce company's strategy of pricing Kindle Fire tablets at near-cost to sell its other products and services. It has specifications similar to high- and mid-range smartphones and runs on a modified version of Google's Android operating system.