5 STARS! My dog began to nuisance bark 2 weeks ago on a Wednesday (We will call that "day 1") and barked again all day on Day 2. On Day 3 I jumped online and wound up here. I ordered my collar which arrived on Day 7 (only 3 working days, SUPER FAST POST!) I charged it that evening and popped it straight on her the very next day. Since then there has been absolutely no barking (I think the feeling of the collar at the lowest level of correction with just 1 bark is working for her) I am very pleased with the instant results, with this very modern "learning" type system that ramps up and down depending on how much barking there is (we have cameras that we can watch her on, how we discovered she was barking in the first place, upset at the neighbourhood renovations) and she is now completely relaxed and chilled out, doing her regular dog stuff instead of patrolling and barking. I HIGHLY RECOMMEND THIS COLLAR.