Top accessory is the tin tube with a handle on it and a metal grill near the bottom - fill with charcoal/briquettes with a firelighter at the bottom, stand tube on lower BBQ grill on top of second (lit) firelighter. Leave for 25 mins and then pour grey, ready to cook charcoal either on inside or outside of wire restrainer thingies and crack on. Made by Weber, about £8 in the shops.
Have done 16lb Christmas Turkey using indirect cooking - fabulous but don't forget to use a foil tray full of water to help steam it and keep it moist.