Features:  & 12304;High Configuration& 12305; Android 9.0 operating system, quad-core processor, stable and reliable, simple operation, strong compatibility. 2G+16G large memory, running multiple tasks at the same time, still smooth and not stuck. Support NFC function.  & 12304;Built-in Barcode Scanner& 12305; High performance 1D/2D scanning engine, which can quickly scan and identify 1D/2D/QR barcode, high reflective barcode, frayed barcode, fuzzy barcode and screen barcode, ideal for inventory, warehouse, logistics, retail, etc.  & 12304;Multiple Network Modes& 12305; Support 4G, 3G, 2G, BT and WiFi network modes, and make business data interconnection more stable and efficient, free from geographical restrictions, enjoy high-quality network communication and rapid data transmission anytime and anywhere.  & 12304;Long Endurance & Durable& 12305; Built-in 3750mAh Li-ion polymer battery, high performance and low consumption processor, long life, ensuring the smooth progress of the work. Made of high quality ABS and PC materials, enabling the terminal durable and has long service life.  & 12304;Ergonomic Design& 12305;Equipped with 4 inch color screen and full digital keyboard, realize the good experience of large screen and one hand operation. Newly designed ergonomic scanning angle can effectively reduce wrist movement and fatigue. 5 million rear camera with auto focus function, quickly identify the code  & 12304;Modular Design& 12305;Users can customize and expand according to their needs to meet the needs of various industries. Supports secondary development of software and hardware to meet user needs in an all-round way.    Specification:  Model: 3503M  Dimension : : 170x70x40mm(LxWxH)  Weight:  270g  Display: 4.0 inch IPS, 800*480  OS: Android 9.0  SDK: ZKC SDK  Development Language: JAVA  Touchscreen: Capacitive touchscreen   Battery Built-in non-removable Li-ion polymer battery,3.7V, 3750mAh  Battery Charging time: about 150 minutes  Battery Standby time: about 14 hours of continuous video playback  Port: Serial port, GPIO, I2C, USB Type-C, etc  Card slot: 1*SIM card, 1*TF card, Max 128GB  Adapter: DC 5V, 3A or quick charge adapter   Temperature and humidity: Temperature: -10& 8451;~50& 8451;, humidity: 0~95%  o: Receiver, speaker, mic, vibrator  Video: decode 1080p@30fps H.264/H.265; encode 1080p@30fps H.264   CPU: MTK MT6739, ARM Cortex-A53   CPU cores: Quad-core  CPU frequency: 1.