To find out what device you have, follow these steps:

1. Check the device itself: Look for the model name printed on the back or front, or displayed during start-up.
2. Device settings:
   • For Android: Go to 'Settings' > 'About Phone' or 'About Device' for device name, model number, and manufacturer.
   • For iOS: Go to 'Settings' > 'General' > 'About' for model name and number.
3. Use the IMEI number: Dial *#06# for the IMEI and use an online IMEI checker to lookup your device details.
4. Original packaging: Check the phone’s original packaging for model and manufacturer information.
5. Device documentation: Refer to the user manual or documentation for model details.
6. Check with the retailer: Contact the retailer (or check their receipts or order confirmations) for device information, based on purchase history.

These methods can help in identifying your mobile device. If uncertain, search online with any known features or specifications to see if you can find a match.