These are awarded based on the Splatfest title that you splatted hard to earn, with the winning team rewarded with a few bonus Super Sea Snails in comparison.
Super Sea Snails can be used to upgrade your gear, but you will need to talk to Murch – the lil’ orange guy next to the entrance to Deca Tower in Inkopolis Square.
He will explain that he can use Super Sea Snails to add new slots to any gear that you own, letting you add more abilities to items that you like your Inkling to wear. Adding another slot will cost you one Super Sea Snail, so make sure that you are happy with your choice.
If the slots are already full, Much can re-roll all sub-abilities on a gear item to let you have another go at randomly unlocking them. Again, this will cost you one Super Sea Snail.
This will also see Murch chuck you ability chunks that, once you have enough, can let you put whatever abilities you want in your gear from those collected.
Splatoon 2 is now available exclusively for Nintendo Switch worldwide.