Optus Mobile Broadband Services can be accessed by 10 devices through the 4G Wi-Fi Modem. The modem is compatible with Cat4 cable. The cost of the 2 GB data that comes with this $15 plan works out to $0.0073 per MB. Optus allows excess usage over and above this 2 GB up to a limit of 150 GB. You can always check your usage by logging to 'myaccount' on Optus.co.au