In mini quads every gram counts. The LittleBee is a good quality, small and lightweight ESC.

LittleBee is using a Silabs processor and fast dedicated driver chips. It comes flashed with BLHei Firmware utilizing Oneshot125 communication protocol making it fast and responsive to throttle movements.

This will help keep your weight down.

Features:
• Lightweight
• Small size
• Preflashed with BLHeli Firmware (V14)
• Silabs MCU
• 2-4s LiPoly
• OPTO ESC

Specs:
Input: 2-4s LiPoly
Constant: 20 Amps
Burst: 30 Amps
BEC: No BEC, opto only
Dimensions: 23x12.5x3mm
Weight: 7g (with wires)

Note: this is an OPTO ESC so you will need a 5V BEC to power your flight controller.