Screen size
U8520 DuplexWinner: 3.2"+53%
Watch Buds 21.5"
Quick verdict
U8520 Duplex leads the measured specs 7-6.
Measured wins
U8520 Duplex
7
spec wins
Overall winner
Ties
1
equal specs
Watch Buds 2
6
spec wins
Screen size
Technology
U8520 Duplex
GSM / HSPA
Watch Buds 2
No cellular connectivity
2G bands
U8520 Duplex
GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2
Watch Buds 2
N/A
3G bands
U8520 Duplex
HSDPA 900 / 2100 - SIM 1 only, HSDPA 850 / 1900
Watch Buds 2
N/A
Speed
U8520 Duplex
HSPA 7.2/0.384 Mbps
Resolution
Refresh rate
Peak brightness
Pixel density
CPU speed
RAM
Storage
Main camera
Front camera
Battery
Wired charging
Weight
Thickness
IP rating
Wi‑Fi
Bluetooth
USB
5G support
equal specsNFC
3.5mm jack
SD card
Stereo speakers
Watch Buds 2
No
4G bands
U8520 Duplex
-
Watch Buds 2
N/A
GPRS
U8520 Duplex
-
Watch Buds 2
No
EDGE
U8520 Duplex
-
Watch Buds 2
No
Announced
U8520 Duplex
2011, October. Released 2011, October
Watch Buds 2
2026, April 20
Status
U8520 Duplex
Discontinued
Watch Buds 2
Available. Released 2026, April 20
Dimensions
U8520 Duplex
112 x 57 x 12.7 mm (4.41 x 2.24 x 0.5 in)
Watch Buds 2
47 x 47 x 14.7 mm (1.85 x 1.85 x 0.58 in)
Weight
U8520 Duplex
109 g (3.84 oz)
Watch Buds 2
54.5 g (1.90 oz)
SIM
U8520 Duplex
Dual SIM (Mini-SIM, dual stand-by)
Watch Buds 2
No
Build
U8520 Duplex
-
Watch Buds 2
Titanium alloy frame, glass-fiber reinforced plastic back
Other
U8520 Duplex
-
Watch Buds 2
Built-in wireless earbuds housed beneath the display; charging from the watch Compatible with standard 22mm straps
Type
U8520 Duplex
TFT, 256K colors
Watch Buds 2
LTPO AMOLED, 3000 nits (peak)
Size
U8520 Duplex
3.2 inches, 30.5 cm2 (~47.8% screen-to-body ratio)
Watch Buds 2
1.5 inches
Resolution
U8520 Duplex
320 x 480 pixels, 3:2 ratio (~180 ppi density)
Watch Buds 2
466 x 466 pixels (~310 ppi density)
OS
U8520 Duplex
Android 2.2 (Froyo)
Watch Buds 2
HarmonyOS
Chipset
U8520 Duplex
Qualcomm MSM7227-1 Snapdragon S1
Watch Buds 2
-
CPU
U8520 Duplex
600 MHz ARM 11
Watch Buds 2
-
GPU
U8520 Duplex
Adreno 200
Watch Buds 2
-
Card slot
U8520 Duplex
microSDHC (dedicated slot), 2 GB included
Watch Buds 2
No
Internal
U8520 Duplex
512MB 256MB RAM
Watch Buds 2
-
Single
U8520 Duplex
3.15 MP
Watch Buds 2
-
Video
U8520 Duplex
480p
Watch Buds 2
-
Single
U8520 Duplex
VGA
Watch Buds 2
-
Video
U8520 Duplex
Watch Buds 2
-
Loudspeaker
U8520 Duplex
Yes
Watch Buds 2
No
3.5mm jack
U8520 Duplex
Yes
Watch Buds 2
No
WLAN
U8520 Duplex
Wi-Fi 802.11 b/g/n
Watch Buds 2
No
Bluetooth
U8520 Duplex
2.1, A2DP, EDR
Watch Buds 2
5.2, A2DP, LE
Positioning
U8520 Duplex
GPS, A-GPS
Watch Buds 2
GPS, GLONASS, GALILEO, BDS
Radio
U8520 Duplex
Stereo FM radio
Watch Buds 2
No
USB
U8520 Duplex
microUSB 2.0
Watch Buds 2
No
NFC
U8520 Duplex
-
Watch Buds 2
Yes
Sensors
U8520 Duplex
Accelerometer, proximity, compass
Watch Buds 2
Accelerometer, gyro, heart rate, SpO2
Other
U8520 Duplex
MP3/WAV/eAAC+ player MP4/H.264 player Organizer Document viewer Photo viewer/editor Voice memo/dial Predictive text input
Watch Buds 2
-
Type
U8520 Duplex
Removable Li-Ion 1500 mAh battery
Watch Buds 2
Li-Ion 410 mAh
Stand-by
U8520 Duplex
Up to 120 h (2G) / Up to 120 h (3G)
Watch Buds 2
-
Talk time
U8520 Duplex
Up to 7 h (2G) / Up to 7 h 30 min (3G)
Watch Buds 2
-
Music play
U8520 Duplex
Up to 20 h
Watch Buds 2
-
Charging
U8520 Duplex
-
Watch Buds 2
Wireless
Colors
U8520 Duplex
Black
Watch Buds 2
Black, Silver
Price
U8520 Duplex
About 110 EUR
Watch Buds 2
About 440 EUR
Models
U8520 Duplex
-
Watch Buds 2
LBA-B19
Other
U8520 Duplex
-
Watch Buds 2
No