These Skull & Wrenches stickers are for both Indoor / Outdoor use. Normally the Skull & Wrenches Evil One® Biker Stickers are $2.00, but they are now only $1 each.
Next, the Skull & Wrenches stickers are a 3.9 inch computer-cut biker sticker / decal. So, the inside of the ring and everything besides the Skull & Wrenches is cut out. Then when you apply the sticker the part beyond the ring is not on the window (aka it is a round looking computer cut decal).
Finally, you might also want to check out our indoor-only Skull & Pistons Evil One® Logo Biker Stickers.