When adding your PowerBase to your cart, you will see the options to purchase with or without the 'Wall Charger Plug". The Quick Charge plug is a higher output wall plug that can deliver 18W output. This plug is required in order to be able to give the PowerBase the minimum power input it needs to work and to charge the Apple Watch port. Standard Apple wall chargers are usually 5V 1A (5W) and will not give the necessary output. If you already own a quick charge plug you may choose to use this and not add the option to your PowerBase order.