The Clan Support item can be purchased in the store under «Other». When purchased you will receive a 1.5x XP boost, and every member of your clan will get an additional 2% XP boost! It will also make your clan emblem visible during the pre-game menu.
The Clan Support will last 3 days.
If you change clans during this three day period, the Clan Support will be applied to your new clan.