Instruction: Extract the value of the target attribute from the given product information and output it along with the corresponding source.

Input:
Product title: Unlocked Android 2.2 Mobile Phone Dual SIM A3000 Smart Phone
Product description: Features Overview: # Operation System: Android 2.2 # WIFI: 802.11b/g wireless internet # Dual sim cards dual standby # Gravity Sensor, Java 2.0, Analog TV, FM Radio, MailBox, Youtube, MSN, Google Maps # Google Market:Support download some applications for free in the Google Market, as long as you register a gmail account # It is a smartphone Technical Specification # Operation System: Android v2.2 # CPU: MediaTek MTK6516,416MHZ # Quad Band: GSM850/900/1800/1900MHZ # Dual sim cards dual standby # Screen: 3.2 inch high definition touch screen, QVGA, 320x480 # Camera: 3.0MP cameras with dual flash light, put out the biggest size is 2048x1536 # MP3 background play, equalizer # Video: 3GP, MP4, full screen, forward and pause # WIFI: 802.11b/g wireless internet # Support Java, can install applications # Free analog TV supported # Support FM radio # Bluetooth A2DP # Sound recorder, Video player, Stereo Speaker # Support MSN, Facebook, eBuddy, Google Maps # Memory: RAM 256M, ROM 512M, exend TF card to 16GB max (NOT included in this package) # Telephone directories: 1000 groups of contacts, support caller ringtone, caller picture # Games: support google android APK games # Calendar/Caculator/Tasks /Alarm clock/World time/Currency Converter/Unit Converter/Stopwatch/Handwriting/Compass/E-book(TXT)/Memory extended.. # Talk time: Up to 2 hours # Standby time: Up to 120 hours # Language:English/French/Spanish/Portuguese/Italian/Russian/Chinese # Weight: Approx 117g # Size: 109x58x13mm
Product feature: Operation System: Android 2.2, WIFI: 802.11b/g wireless internet, Dual sim cards dual standby, Gravity Sensor, Java 2.0, Analog TV, FM Radio, MailBox, Youtube, MSN, Google Maps, oogle Market:Support download some applications for free in the Google Market, as long as you register a gmail account
Product brand: A3000
Target attributes: SIM Slots
Answer: attribute: sim slots
value: dual sim
source: product feature
attribute: sim slots
value: dual sim
source: product title
attribute: sim slots
value: dual sim
source: product description