Screen size
C211.3"
U1Winner: 1.9"+32%
Quick verdict
U1 leads the measured specs 4-3.
Measured wins
C21
3
spec wins
Ties
5
equal specs
U1
4
spec wins
Overall winner
Screen size
Technology
C21
No cellular connectivity
U1
No cellular connectivity
2G bands
C21
N/A
U1
N/A
3G bands
C21
N/A
U1
N/A
4G bands
C21
N/A
U1
N/A
Resolution
Refresh rate
Peak brightness
Pixel density
CPU speed
RAM
Storage
Main camera
Front camera
Battery
equal specsWired charging
Weight
Thickness
IP rating
Wi‑Fi
Bluetooth
USB
5G support
equal specsNFC
equal specs3.5mm jack
equal specsSD card
equal specsStereo speakers
Speed
C21
No
U1
No
GPRS
C21
No
U1
No
EDGE
C21
No
U1
No
Announced
C21
2023, November
U1
2025, February
Status
C21
Available. Released 2023, November
U1
Available. Released 2025, February
Dimensions
C21
46.5 x 46.5 x 13 mm (1.83 x 1.83 x 0.51 in)
U1
49.8 x 42.4 x 11.4 mm (1.96 x 1.67 x 0.45 in)
Weight
C21
-
U1
43.8 g (1.55 oz)
Build
C21
Zinc alloy frame
U1
-
SIM
C21
No
U1
No
Other
C21
IP68 dust tight and water resistant (immersible up to 1.5m for 30 min)
U1
Waterproof (1ATM)
Type
C21
TFT LCD
U1
TFT LCD
Size
C21
1.32 inches
U1
1.93 inches
Resolution
C21
360 x 360 pixels (~386 ppi density)
U1
240 x 288 pixels (~194 ppi density)
Protection
C21
Corning Gorilla Glass
U1
-
OS
C21
Proprietary OS
U1
Proprietary OS
Card slot
C21
No
U1
No
Internal
C21
128MB
U1
16MB
Other
C21
No
U1
No
Loudspeaker
C21
No
U1
Yes
3.5mm jack
C21
No
U1
No
WLAN
C21
No
U1
No
Bluetooth
C21
5.0, A2DP
U1
5.4, A2DP, LE
Positioning
C21
No
U1
No
NFC
C21
No
U1
No
Radio
C21
No
U1
No
USB
C21
No
U1
No
Sensors
C21
Accelerometer, heart rate, SpO2, blood pressure
U1
Accelerometer, gyro, heart rate, SpO2
Type
C21
300 mAh
U1
300 mAh
Colors
C21
Black, Silver
U1
Black, Pink
Price
C21
About 40 EUR
U1
-