Purchasing this grants you access to the premium track of the daily rewards inside the gui menu. Open your gui and navigate to daily rewards to view the possible items you can get upon purchasing this. The premium track purchase only works for the current season, daily rewards require you to log on every day to claim the rewards, you will not accumulate rewards by being offline. Your progress on the daily rewards track will not reset if you miss a day! 

Purchasing this item after having claimed free daily reward track items will allow you to catch up to your current spot in the daily rewards track, so you can purchase this premium track after completing the free track and get all the items at once.