SkyTrak can be used either inside or outside depending on your requirements. As with all these things, if you are using indoors just make sure you have plenty of space to swing free from anything breakable! If you are using the unit outdoors, you will get around 4 hours of continuous use from the battery.
Can you use SkyTrak on grass?
The unit itself projects a red dot onto the hitting mat and you place the ball at that spot so the camera can pick up the impact. As a result, sunlight, grass and SkyTrak simply don't mix.
Can you use SkyTrak in the rain?
The weather
If you have the facility to put a roof over your hitting area then you can even use Skytrak in the rain.