This is the Arrma Mega Electronic Speed Control for Brushed Motors 12 Turns and Above.
FEATURES
Compatible with 550 size motors down to 12 turns and powered by a 2S LiPo or a 6-cell NiMH battery, or an 18 turn & above 550 size motor with 3S LiPo or 9-cell NiMH battery power
Aluminum heat sink, red in color
Handles up to 40A
INCLUDES
Arrma Mega 12T ESC with T-Plug Battery Connector, Receiver Connector, On/Off Switch and Instructions