📌[New Difference from Hollyland Mars 300 Pro] A 3-in-1 thumbwheel switch menu is added to Hollyland MARS 300 PRO together with a side OLED screen with easy access to the device's power status, channel scan result, video input, channel number, etc., so now people don't have to worry about having their screen blocked when they mount their systems horizontally on the camera. | 📌[Fan Speed Control] New added function to adjust the fan speed in order to control fan noise. Regular speed to keep the fan running at its own pace, or low speed for quiet mode when one sets a microphone next to the transmitter. | 📌[Channel Scan & APP Monitoring] Hollyland MARS 300 PRO also comes with channel scan on both the receiver and the App, so people can easily identify the best channel to use on a shooting location ahead of time, or anytime. System upgradation can be made through HollyView App, you only need to click your phone screen, and the upgradation for Hollyland Mars 300 PRO is done! Please refer to the manual for detailed operation. | 📌[2-Way Charging] Hollyland MARS 300 PRO supports 5-12V wide voltage power supply, including various L-series batteries, different power banks, and Type-C charging. | 📌[3 Versions & 1 Year Guarantee] There are 3 versions of Hollyland MARS 300 PRO, Single Transmitter version, Standard version and Enhanced version. Built-in antennas are introduced to Hollyland MARS 300 PRO for easy setup, efficient shooting, and different shooting applications. Standard and Enhanced versions come with receivers with built-in antennas.