This pack includes 2 sets of AS150 connectors, with 2 anti-spark connectors. The anti-spark connector is normally fitted to the positive wire.
The negative wire is connected first, then the positive wire with the anti-spark connector.
The anti-spark connector allows a two stage connection to the speed controller. Initially the tip of the anti spark plug is connected to the battery, allowing it to slowly charge the capacitors in the speed controller via the resistor inside the connector. By the time the main body of the connector makes contact, the capacitors will be pre-charged to the battery voltage, avoiding any sparks.