2000 Watt Heavy Duty Step Up/Down Voltage Transformer Converter, 110/120/220/240 V, 5V USB Port

Ordered this 500 Watt transformer to use an appliance from Korea in the U.S.A. Per the manufacturer, I computed the amount of wattage needed for the appliance and then doubled it. So for example, I computed that my appliance required 210 watts, so I doubled to 420 and rounded up. The appliance I have (from Korea) didn't specify the wattage using "Watt" or "W", but instead said "VA". I believe this is the same or equivalent, but you should check with a qualified electrician if this is the case with your appliance. If your unit shows just Amp or Voltage, you can multiply the two to arrive at Wattage. Again, check with someone who is qualified before using the appliance or ordering a unit so you can ensure you get the correct wattage. My calculations worked well and the appliance has functioned without problems under constant load the entire time without issues at the selected wattage. My understanding is that you'll want to double the wattage due to changes in the flow of electricity and the appliance's peak demands that could exceed the normal wattage used or identified on the back of the appliance. Be careful for laser printers or microwaves (and other high wattage appliances), I believe that can have peak watt use of much greater than their rated wattage. I believe the rule of thumb is to multiply by 3 instead of 2 to arrive at the wattage of transformer you will need. If you live in a country that has inconsistent power delivery, you may consider purchasing a separate unit that regulates the voltage. Some transformers have this built in, but this one does not. If you will be using this transformer in the U.S.A. on a modern electrical circuit, you probably do not need a regulator. I did not purchase one and have had no trouble in the month of so that I've used the unit. The transformer does get warm to the touch, but does not get hot. I expect to unplug and turn off this transformer during vacations and while away from the home for a long period of time, but I believe that this should function well under constant load indefinitely. When you plug in, make sure you select the correct voltage on the back as the removable plug should represent the SOURCE voltage of the electricity that you will be plugging the transformer INTO. In my case, I was using a 220V appliance in the U.S.A. (110V) so I selected 110V on the back and plugged the appliance into the 220V plug on the front. For some reason, I found this a bit confusing so make sure you read the instructions included with the unit. This transformer comes with a quality plug converted for U.S. style plugs (110V) to the European/Asian style (220V) which is useful if you travel internationally and have a dual 110/220V appliance (like cell phones, laptops, etc.). It may come in helpful if you need to convert plugs for the appliance you'll be using with the transformer. In general, the unit feels like it's well made and will be able to withstand a long period of consistent use. The transformer I received was cosmetically damaged during shipment (one corner bent and a few scratches). However I'm hiding this transformer behind some kitchen items so it's not a beauty contest. The unit held up well to shipment and I didn't think the scratches and bent corner warranted a return. As far as the value of the unit is concerned, I'm very pleased with the purchase. This unit appears to be quality and will last quite a while. It was less expensive than similar units and was available for delivery with Amazon Prime. The unit includes a 3-year warranty. With this transformer being used under a constant load 24/7 almost every day, I'm comfortable that all the quality issues with the unit should come out in the first 3 years. Overall: good value, quality unit, and fast free delivery with Amazon Prime. Recommended!

This converter has been a lifesaver for us. We brought our coffee machine from Europe to the U.S. a few years ago, and thanks to this transformer, we’ve been able to use it every day without any issues. The quality has been great so far, and it hasn’t let us down at all. We’re still enjoying our machine just like back home. Highly recommend!

I consider myself a fairly intelligent person. My intelligence is well above average. I follow directions well. No, I follow directions exceptionally well. These directions are not only the WORST directions ever written, they are completely wrong. Even though I knew nothing about transformers, while I was setting this thing up, it seemed counter-intuitive. I bought a yogurt maker back from Asia. I was so excited to have finally gotten my shipment of this item in the early afternoon, I ripped open the box and went to work straight-away. Ugh. The dumb directions were so confusingly written, it took me a frustrating few minutes to try to figure it out. I had a 220V item, I needed to convert to 110V. According to the paper, I was supposed to select the input at 220V and plug my appliance into the 110V. It didn't seem right to me, but I plugged it in and set the timer for 8 hours. 10:30 at night the beeper on the yogurt maker sounded. I had seen this appliance being used in Asia, and my stepmother who cannot cook, showed me I just pour in a little yogurt drink and fill it up with milk. I had bought greek yogurt, put in 2/3 of a cup of it and filled the rest with milk. I excitedly opened the jar, and found a lump of yogurt floating in milk. I was confused. Maybe it was because I didn't use a liquid yogurt? But it had the correct bacteria in it, what went wrong? No, it couldn't be the directions to the transformer! Why would they send out wrong directions? The typo should have cued me but instead I re-read the directions, and confirmed I did everything correctly. I Googled how to make yogurt with a yogurt maker. These crazy directions about heating up milk and cooling it came up. But wait, I SAW my stepmother pour liquids and it came out yogurt 8 hours later and there was no heating milk involved. I Googled Rockstone Transformer and descriptions of the item came up. I decided, maybe I didn't add enough starter yogurt, so I added more and started the cycle again. And perhaps this time I should try the output plug that says 220V, as we all know the definition of insanity is repeating oneself expecting a different outcome. I was convinced it was going to start a fire, and my husband asked me if I wanted to move it to the bedroom just in case it did. Yes, because I want us and my wardrobe to burn first!!! Thankfully my last Google search was " How to use a voltage converter transformer" and a Wiki article came up. Now THOSE are properly written directions. The input should have been selected to 110V, because duh we are in America and it's 110V. I Love Wiki; I slept like a baby. Woke up the next morning and voila, yogurt made and apartment not burned down. Long story short, on a low watt item, putting the input in at 220V and using the output 110V is not going to A. ruin the transformer or B. start a fire, but it will definitely not make yogurt. I would have given this 5 stars as it really is a great looking and functional item that's super reasonably priced, however for making me feel like an idiot and wasting 9 plus hours of my time, I'm going to have to deduct. Note to manufacturer, go Google wiki and write proper directions and fix the typo!!! I'm feeling a bit Kathleen Turner/Serial Mom-ish, but what can I say. I'm above average intelligent ;)

This transformer has been a life saver! It has effectively served its purpose for the last 3 years. I haven't even had to change the fuse yet. I use it for my Keurig coffee maker everyday and on occasion my Kitchenaid hand-mixer. Because I only have 1 outlet on that side of the kitchen, I have also used a coffee grinder with an EU plug with no issues. I think these devices definitely are worth the cost and hold their value. It is quite heavy and takes up a lot of space in your luggage, but it's worth every penny. Make sure that the model you purchase is specific to the country/region you are going to. The one I purchased has an adapter to plug from EU to US. I'm referring to the power supply cord in this instance.

Don't buy this crap the smell coming out from this causes headache and you are gonna suffer

Lo adquirí bajo la asunción que sería útil para colocarlo entre una toma de corriente residencial en Cd. México (110-120V) y activar una caminadora de uso rudo (220V). Desafortunadamente no logré el objetivo, quedándome con el convertidor de corriente sin uso... Será posible cambiarlo por otro producto?. Gracias.

The Transformer had come in good condition. But the adapter had come damaged. Had proper care been taken while packing, this could have been avoided.

I bought this for my vitamix grinder and it is working perfectly well with it

Best converter, product received as describe no issue at all when using it. No problem in converting appliances from US. Been using it everyday and it has been a lifesaver. One thing to add, the whole experience was much easier because of their Customer Service. They assured me of the product and also when will the order arrived as i really need it urgently. And they even give a extra discount which was really pleasing, and how they approached was really a personal experience for me. Will definitely recommend any product from them.