I have before 2 1/2 years 10 ordered from these stones. These are installed outdoors - unfortunately occurs but always a moisture or the batteries go kaput. After a year I had 50% failure at 2 years and the remaining stones are broken. I have now ordered one last time - then I'll probably still switch to a different solution.
Conclusion: For the optics 5 stars, the quality gets unfortunately only 2 stars.