I've decided to purchase an EMS400 at the London tattoo convention last september 2013 at a certain booth HM supplies but went home with a non proper functional unit, emailed the company a few times and got a good response and had a replacement sent to me. It went well for like a week or so and guess what, the unit failed again as it was doin the same faulty functions like the unit keeps beeping, the voltage goes down to zero by itself, the timer mode sets itself, and the worst thing is the unit turns itself OFF. I've emailed the company again and got a respond but it took them like ages to do so and they didn't even make actions of replacing the faulty unit that serves as a replacement???