Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: Soundstream VIR7355NRBT 7-Inch Wide Double Din Monitor (Black)
Product description: 7" Wide Touch Screen EXACT Double-din In-Dash Motorized TFT Monitor/DVD/AM/FM with Bluetooth
Product feature: Bluetooth & Navigation Input(Requires NAVIBOX-1) 7 Wide Touch Screen EXACT Double-din In-Dash Motorized TFT Monitor/DVD/AM/FM, Motorized TFT-LCD w/ 4 Pre-Set Angles & Last Angle Memory Car-Spec DVD Transport for Extreme Temperature Exposure Playback from DVDR/RW & CDR/RW Including VCD MP3 MP4 & DiviX, Recall Memory for Last DVD Position i-Pod Input Connection (requires IC-1) Mini-USB Connection for MP3 & MP4 Playback From 4gb Flash Drive SD Card Reader for MP3 MP4 DiviX & Xvid Playback, A/V Outputs for Multiple Components A/V Inputs for Secondary Source Front Panel 3.5mm Auxiliary A/V Input Reverse Camera Input w/ Trigger, 18 FM / 12 AM Station Memory 50w x 4 MOSFET Powered Speaker Level Outputs Front & Rear Pre-Amp Outputs Variable Subwoofer Pre-Amp Output w/ LPF (80 120 160Hz)
Product brand: Soundstream
Target attributes: Screen Size
Answer: attribute: screen size
value: 7"
source: product description
attribute: screen size
value: 7-inch
source: product title