Samsung Galaxy A03s (4/64GB) likely had the following key features:

1. Display: It likely featured a large display, possibly around 6.5 inches, with an HD+ resolution.

2. Processor: The phone likely housed a mid-range or budget processor suitable for everyday tasks and moderate multitasking.

3. RAM and Storage: The variant you mentioned, "4/64GB," suggests it had 4 GB of RAM for smoother performance and 64 GB of internal storage for storing apps, files, and media. It may also have had expandable storage using a microSD card.

4. Camera: Expect a basic camera setup, possibly with a combination of a main camera, ultra-wide lens, and depth sensor. The megapixel count may vary.

5. Battery: A decent-sized battery, probably over 4000 mAh, to provide a satisfactory battery life.

6. Operating System: It likely ran on Android, with Samsung's One UI skin on top.

7. Connectivity: Standard connectivity options such as 4G LTE, Wi-Fi, Bluetooth, and a USB Type-C port.

8. Design: Samsung's Galaxy A series typically features modern designs, and the A03s may have had a plastic build to keep costs down.

Keep in mind that specifications may vary based on region and updates released after my last knowledge update. For the most accurate and up-to-date information, it's recommended to check the official Samsung website or contact a reliable retailer.