This little item, while increasing in price since I first purchased many years ago, is fantastic. I have got virtually every electric fence tester on the market and this is the only one that is consistently reliable. I have one on each bunch of keys for my fields and would not be without it as it is handy, quick and easy. Thought I had ruined one by putting it through the washing machine and it 'sang' at me until I took it apart, dried it out and fitted a new battery, and now working perfectly again. Would be lost without it. Thank you.