| Local Name | X21 UD |
| Technology | GSM / CDMA / HSPA / LTE |
| 4G Bands | LTE band 1(2100), 2(1900), 3(1800), 5(850), 8(900), 34(2000), 38(2600), 39(1900), 40(2300), 41(2500) |
| 3G Bands | HSDPA 850 / 900 / 1900 / 2100 |
| 2G Bands | GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2 | CDMA 800 & TD-SCDMA |
| Speed | HSPA 42.2/5.76 Mbps, LTE-A (2CA) Cat6 300/50 Mbps |
| GPRS | Yes |
| EDGE | Yes |
| Announced | 2018, March |
| Status | Available. Released 2018, March |
| Dimensions | 154.5 x 74.8 x 7.4 mm (6.08 x 2.94 x 0.29 in) |
| Weight | 156.2 g (5.50 oz) |
| Build | Front glass, aluminum body |
| SIM | Hybrid Dual SIM (Nano-SIM, dual stand-by) |
| Display Type | Super AMOLED capacitive touchscreen, 16M colors |
| Screen Size | 6.28 inches, 98.4 cm2 (~85.2% screen-to-body ratio) |
| Resolution | 1080 x 2280 pixels, 19:9 ratio (~402 ppi density) |
| Protection | Corning Gorilla Glass 3 |
| OS | Android 8.1 (Oreo); Funtouch 4 |
| Chipset | Qualcomm SDM660 Snapdragon 660 (14 nm) |
| CPU | Octa-core (4x2.2 GHz Kryo 260 & 4x1.8 GHz Kryo 260) |
| GPU | Adreno 512 |
| Card Slot | microSD, up to 256 GB (uses shared SIM slot) |
| Internal Memory | 128 GB, 6 GB RAM |
| Camera Features | LED flash, HDR, panorama |
| Video | 1080p@30fps |
| Loudspeaker | Yes |
| 3.5mm Jack | Yes |
| Sound | 32-bit/192kHz audio Active noise cancellation with dedicated mic |
| WLAN | Wi-Fi 802.11 a/b/g/n/ac, dual-band, WiFi Direct, hotspot |
| Bluetooth | 5.0, A2DP, LE |
| GPS | Yes, with A-GPS, GLONASS |
| Radio | FM radio |
| USB | microUSB 2.0, USB On-The-Go |
| Sensors | Fingerprint (under display), accelerometer, proximity, compass |
| Battery | Non-removable Li-Ion 3200 mAh battery |
| Colors | Black, Ruby Red |
