Feature: l Brand new and high quality l Small size and lightweight, do not increase burden to the motor l Heat sink w/ cooling fan that can effectively prevent the motor from overheating, and extend its service life l Suitable for brushed 540/550 and brushless 3650/3660 motor l Universal suitable for 1/10 HSP 94111 94123 94107 94170, etc RC car motor with outer diameter of 3.5-3.7cm Specification: l Style: Style 1, Style 2, Style 3 (As Shown) l Fan Input Voltage: 4.8-6V (Suitable for Receiving Power) Package: l 1x Heat Sink