There are two braking systems: The hand brake which presses on the rear wheel and your shoe.
Primary Braking System
Pull the hand brake lever to engage the rear brake. This break is not effective to stop when going down steep inclines and will place significant wear on the wheel if used for long shallow grades. In this case use the "shoe" method instead.
More information needs to be written here. Especially how and when to adjust the tension on the brakes, and how to prevent the brake cable from crimping when the motorboard is folded.
It is necessary to periodically checking for flat spots. Position the Tire Gauge on the rear tire according to instructions. Run the Tire Gauge along the tire, and make sure it maintains full contact with the tire. Any flat spots, bald, or skidded areas in the tire should become apparent.
Tires will last somewhat longer if the hand brake is used as little as possible.
Secondary Braking System
As with all scooters, the secondary braking system on the motorboard is engaged by placing the heel of your shoe on top of the rear wheel, and applying pressure. By varying the amount of pressure, you can vary the amount of braking power.
Make sure that you are wearing appropriate footwear in order to stop the motorboard in this way. This technique is especially effective when riding down small hills.