5.5" and 1.5 GB RAM are striking.
Battery life seems low.
The SoC might be a bit weak, 1.1GHz quad - not clear what it actually is…
Specs from http://www.optus.com.au/shop/prepaidmobile/optus/x-smart
Display 5.5" HD IPS 720 x 1280
Size (H X W X D) 151 x 77 x 7.99 mm
Weight 151g
Color Dark Grey
Processor 1.1GHz Quad core
RAM 1.5GB
Internal memory Up to 16GB (actual formatted capacity will be less)
Expandable Memory Supports microSD up to 128GB
Camera
Rear: 8MP with flash
Front: 5MP with flash
Video 720P @ 30fps
Connectivity
Bluetooth 4.1
WiFi: 802.11 a/b/g/n
GPS: Yes
NFC: No
3.5mm audio jack: Yes
FM radio: No
Operating System Android 6.0
SIM Card compatibility Micro
3G Network 900/2100MHz
4G Network
FDD: 700/1800/2100/2600 MHz
TDD: 2300 MHz
Battery Capacity 2500 mAh
Battery Usage
3G standby time: Up to 500 hours
3G talk time: Up to 15 hours
Audio playback: Up to 7 hours
Battery is quite small too… 15 hours of talk time when the average of most devices nowadays is rated around 21 hours.
EDIT: After a bit of sleuthing, this appears to be a rebadged Alcatel Pop 4+
http://www.gsmarena.com/alcatel_pop_4+-7936.php
It runs a pretty pokey Snapdragon 210 (Cortex A7 series) with Adreno 304 GPU.