ManaPlus/data/graphics/gui/equipment_background.xml

<?xml version="1.0" encoding="utf-8"?>
<skinset name="Default" image="window.png">
    <widget type="Window" xpos="96" ypos="220">
        <part type="standart" xpos="0" ypos="0" width="36" height="36" />
        <part type="highlighted" xpos="36" ypos="0" width="36" height="36" />
    </widget>
</skinset>