12/23/19- Update: I have been hounded to delete my review by this company. Latest bribe has been to give me $45 to delete my review. Shady company. 1/18/19- sent back to Amazon and received a prompt refund as soon as it shipped. If I was able to rate the refund process separately, I would give it 5-stars. I tried this collar on my rescued Boston Terrier who had AWFUL separation anxiety. Picked this up on a "lightning deal" on Amazon for $30. Just like always, you get what you pay for. If you are looking at using a "shock collar" in your dog training regiment, then save your money and get an E-collar. 4x the price, but SOOOOO worth it. This collar was laggy, unresponsive at times and very cheaply made. I've been using the E-collar for a week and it is amazing. It is like the difference between driving a 1970 VW Bug and then hopping into a brand new car with all the bells and whistles. Not fair to compare this shock collar to the E-collar. Different classes.