From the manufacturer

Infinity O Display & Snapdragon 675 Processor 
16.0 cm (6.3”) FHD+ Infinity O Display
A completely immersive viewing experience with a near bezel-less 16.0 cm (6.3”) FHD+ display, 91.8% Screen Ratio and Corning Gorilla Glass

Snapdragon 675 Processor with LPDDR4x RAM
Qualcomm Snapdragon 675 mobile platform with 6GB LPDDR4x RAM, Qualcomm Adreno 612 GPU. 128 GB Storage with expandable memory slot upto 512 GB.
32 MP Triple Rear Camera
Triple Rear Camera – 32MP/F1.7 Primary Camera | 5MP/F2.2 Live Focus | 8MP/123 degree Ultra-Wide Lens
16 MP Front Camera
16 MP Front Camera with F2.0 Aperture
4K Video Recording
4K Video Recording, Super slow-mo @240fps, Hyperlapse, Ultra-Wide Video
1 32 MP Triple Rear Camera
2 16 MP Front Camera
3 4K Video Recording
Design
7.9 mm sleek body and premium dual tone finish
Battery
3500 mAh Battery with 15W Type C Fast Charger
Android Pie
Android Pie Operating System with OneUI
Security
Fast Face Unlock and Finger Print Sensor
Screen Sound Technology
Screen sound technology transforms your screen into a speaker
1 Design
2 Battery
3 Android Pie
4 Security
5 Screen Sound Technology
How do I listen to music if there is no 3.5mm headphone jack?
M40 comes with USB Type C earphones in-box. In addition, it also supports dolby atmos on wired and wireless earphones/headphones
What is On-Screen Sound Technology?
To give you a bezel-free experience, the in-call speaker grill has been replaced by the On-Screen Sound technology. (OST) The entire display acts as a speaker, allowing the user to hold the device in multiple orientations while calling.
What are the sensors on this device?
Accelerometer,Fingerprint Sensor,Gyro Sensor,Geomagnetic Sensor,Hall Sensor,Proximity Sensor,Virtual Light Sensing
What is the SAR value of this device?
0.200 W/Kg is the Head SAR value of the device
32MP + 8MP + 5MP triple rear camera | 16MP front facing camera
16.00 centimeters (6.3-inch) FHD+ capacitive touchscreen with 2340 x 1080 pixels resolution 16M color support
Memory, Storage & SIM: 6GB RAM | 128GB storage expandable up to 512GB with Hybrid slot | Dual nano SIM with dual standby (4G+4G)
Android v9 Pie operating system with 2GHz, 1.7 GHz Qualcomm Snapdragon SD 675 octa core processor
3500mAH lithium-ion battery, CPU: Upto 2 GHz Octa-core, 11nm
1 year manufacturer warranty for device and 6 months manufacturer warranty for in-box accessories including batteries from the date of purchase
Box also includes: Travel Adapter, USB Cable, Type C Earphones, Ejection Pin and User Manual