Squash Headband
From Inkipedia, the Splatoon wiki
The Squash Headband is a type of headgear in Splatoon. It is a 1-star item produced by Zink and comes with the main ability Damage Up.
This item can be purchased from Cooler Heads for 400 Cash.
Appearance
The Squash Headband is a light-blue headband with Inkling text going around half of the headband. The text matches the other text located under Zink's logo.