Yes!
For our Outdoor neon sign in order to make it water resistant, we use a 10 mm acrylic backing, carve the original design into the acrylic board and attach the LED tube into the carved niche.
The indoor sign is suitable for weather between -4 to +104 degrees Fahrenheit. If your signs doesn't have to be waterproof, the indoor signs can be used outdoor.
* Please note: Whether you are interested in adding a dimmer, it will have to be positioned indoors as there is no waterproof dimmer for these signs.