Item Rarity Booster

I want to buy a item rarity booster, but a question
I have 575% luck now, it’s boost 100%, that mean i’ll got 575% * 2 or 575% + 100% ?
Tags some : @Refia @SteigerBox < Developer and admin maybe know >

Don’t worry…I hear Dungeon Claus is going to bring a free Item Rarity Boost to all the players this week…

I already had that boost and it was only 15 mins. Its great i guess if i want rare legends but I don’t often use nadroji and that to find rare legends. Regardless of that, thank you DQ Claus (Developers) for giving rarity hoost to all of us.