So far so good. It works as it should. I've cleaned 2 carburetor's with it and it did great.

The soncation is great. For the price, it's a good value. But the heat control is laughably bad. I set it to "40C" and put a thermometer in and it was like 70C. Sometimes I can set it to 35C and it gets nice and warm, sometimes I set it to 35C and it's scalding hot. So yeah, you gotta monitor it and know that whatever it's reporting is dead wrong. Also, if the water is hotter than the set point, the brain reports the set point as the current temperature...LOL. Bad, and also potentially unsafe. But yeah, other than that it gets the job done.

Oh, one other annoyance: The unit came with a threaded to barb fitting and a length of hose to attach to the drain cock on the side of the unit, but it's not the right size. The threads are too small like they gave me 1/8" smaller pipe size. Of course I don't know what the fitting actually is...probably metric pipe? Who knows.

So, I bought this for my husband to clean his CPAP mask and some other items. I got this one specifically because it would fit the ResMed full sized mask that covers the mouth and nose. Wow !! It works. I filled the tank with warm water, added about three tablespoons of salt and about 6 drops of dawn detergent. Set the timer for 20 minutes, let put the mask in and let it run. it is a bit noisy, but that does not bother me, and lets me know it is working. When it was done, I emptied the tank and put fresh water in it and put the mask back into it and ran for an additional 20 minutes to make sure that all the soap was rinsed off of it, because of fears associated with inhaling a surfactant, and damage to lung tissue. The mask came out clean and fresh smelling. No face oils left, no smell, worked like a dream.

Caution: My husband decided to try using it on one of his pistols. The pistol was a really nice blued weapon. The cleaner removed the bluing off the weapon. Opps. I was not there when they did this, but I think he said that they used vinegar and water as a cleaner.

Thankfully, we have a friend that knows how to re-blue the weapon, but what a pain. Do not use this to clean blued weapons, it will remove the bluing and leave the weapon blotched and mottled.

All good except I wish it would give the option Fahrenheit/Celsius and not just Celsius. Oh well just print a conversion chart laminate it and you are good to go.

TL;DR -- Slightly over-priced for what you get and it does work, but the transducer does not produce the rated power.

I bought the 40A model, which purports to have a 200 watt tank heater and a 240 watt transducer. I put an ammeter on it to test this, and while the heater makes the rated 200 watts (120V @ ~1.9 amps), the transducer only makes about 200 watts (120V @ 1.75 amps). Curiously, this would match the specs for the 30A unit (although the label on this one does say 40A).

The usable tank volume is approximately 11.5" x 9.25" x 4.75" (WHD), which is 505 cubic inches, or 2.2 gallons (~8.3 liters). I'm assuming you're not supposed to fill it past the ridge that's about 1" down from the top. The entire tank volume might be 2.6 gallons (10 liters), but the usable tank volume is not. You're not supposed to set objects on the bottom of the tank, so the included basket further reduces the usable volume of the tank.

The 200 watt heater took over 30 minutes to raise the temperature from 20C to 40C. I didn't do the math to determine how long it should take to raise 2 gallons by 20C degrees, but when you're waiting for it, it's slow. Glacially slow...

The controls work OK, but the front panel of the unit is thin sheet metal, and flexes quite a bit as you're pressing buttons. The manual is what you'd expect from a typical Chinese manual; hard to read and lacking clarity. For instance, if you don't have enough water in the tank, the temperature blinks '01' and although the heater indicator is on, it's not actually heating. You do need to fill the tank a little more than 3/4 full before it decides it has enough fluid to be happy.

When the unit is first turned on, the timer defaults to 5:00 minutes. Once the cycle has completed, it resets back to 0:00. This is a little annoying if you want to run a number of cleaning cycles. I had to keep resetting it to 15 minutes before starting each cycle.

I have no way to measure the transducer frequency, so I'll have to trust that it's indeed 40KHz. The unit is not excessively noisy, but you don't want to run it in your office. It produces a moderately loud buzzing, which is the tank resonating at some frequency.

My overall impression is that I would have found it to be a much better value at $150 than $200. It does clean things; I had a bunch of fairly dirty sockets from a socket wrench set, and it cleaned them up. I used AIM Purple Dragon cleaner, and they came out pretty well. I also cleaned a few bolts from an engine that were greasy and had some rust, and it did OK on those. It's good enough to not return it, but it's no value deal. That being said, I didn't see any other units on Amazon that seemed any better.