Flight Controller (FC):

Processor (F405 V4): This refers to the type of microcontroller or processor used in the flight controller. An F405 processor typically indicates a 32-bit processor, which is common in modern flight controllers.
Size (30×30): The size specification indicates the mounting hole spacing on the board. In this case, it’s 30×30 mm, which is a standard size for many mini and micro quadcopters.

Features:

Flight controllers come with various features such as gyroscopes, accelerometers, and often a barometer for altitude control. They may also support different firmware options like Betaflight, Cleanflight, or iNav.
Electronic Speed Controller (ESC):

Current Rating (55A): The ESC’s current rating refers to the maximum current it can handle. Higher ratings are suitable for more powerful motors and propellers.

BLHeli_S (BLS): BLHeli_S is a firmware for ESCs that provides features like active braking and smoother throttle response. It’s an updated version of the original BLHeli firmware.
Size (30×30): Similar to the flight controller, the size specification for the ESC indicates the mounting hole spacing.

Stack Configuration:

The term “stack” implies that the flight controller and ESC are designed to be stacked on top of each other, reducing the overall footprint and simplifying wiring.

Connectivity:

Look for features like UART ports for connecting peripherals such as GPS modules, receivers, or telemetry devices.
Integrated connectors for motor wires, battery input, and other peripherals make installation and wiring more straightforward.
Integrated OSD (On-Screen Display):

Some flight controllers come with an integrated OSD, allowing you to display important flight information such as battery voltage, flight time, and more on your FPV goggles or monitor.

Package Include:

1x SpeedyBee F405 V4 BLS 55A 30x30 FC & ESC Stack