This single strand of 100 LED lights can be used indoor or outdoor (just make sure the transformer is always protected from the weather).
In the past these came with very large transformers, however the new transformers are small enough to easily fit in power boards if you require more than one set of lights for your Christmas tree.
The string length is 10metres.
We would recommend:
1 x string of 100 for 1.5m tree
1 or 2 x strings of 100 for 1.8m tree
2-3 strings of 100 for 1.98m tree
3-4 strings of 100 for 2.28m tree
These lights can be set to static or twinkling.