These bases are completely free for any project you want to use them for. There's a male and female base, as you can see, with color and shading layers.
Here are my rules:
Do not remove my signature.
Do not claim as your own artwork.
Do not make it into another editable.
Do not make major edits to the original lines.
Do not sell the original bases or any spinoffs for any kinds of profit (CS pets, C$, real-life money, etc.)