The wireless adapter for your notebook pc or any other client device (end device) that you may be using. Here is a small selection to choose from.
From your internet service provider, you can replace the default router from your internet service provider. Get better bandwidth and clearer channels by having 2 frequencies to choose from the standard 2.4Ghz which even your bluetooth device rides on and the newer 5Ghz where there is less users on this frequency. It carries higher wireless bandwidths too.