We first heard about Nite Guard back in 2004 from an online chat group about guineas. We have been using the product now for over 6 years for owls! We have more than 100 free-ranging guineas that roost in our barnyard trees at night. These lights have virtually halted (99% I’d say) the nightly owl attacks since we began using them. We just ordered more to replace some that have stopped working. We are VERY satisfied with the original Nite Guard Solar®!