might make sense just to copy the description under the video which is for 12S but looks like on the picture only for 10S:
Maytech MTBR1812 Rheostatic Brake
Battery: max. 12s
Operation voltage: 57V
Startup time: 200ms
Max current: 5A
Function: When regenerative voltage is higher than operation voltage, Rheostatic Brake starts working and reduces the reverse voltage to protect controllers.
Power Cable 20# AWG Length: 160mm
Black and Red
If you start a trip from the top of a steep hill with a battery, the regenerative output voltage from the controller during high speed braking could exceed the maximum charging voltage of the battery, and under these circumstances, the battery’s BMS to disconnect the charging supply in order to prevent the regenerative braking from overcharging the battery.
When regenerative braking voltage exceeding the maximum charging voltage of the battery, BMS switches off, regenerative braking energy cannot be absorbed by the battery, then the controller of the regenerative braking voltage will continue to rise. After the regenerative braking voltage reached 57V, the electronic switch inside the Rheostatic Brake will start, the energy will be released through special braking resistor, so the braking voltage will be limited. The controller will be protected.
When regenerative braking voltage exceeds maximum charging voltage of the battery, BMS will disconnect.