I purchased three of these power converter modules for a device I will describe in detail later on for those interested. First though, most people will be interested with the discovered defective manufacturing issue so let us start there. If you look at the first image you will see a close up of the heat sink. Note how the heat sink is tilted and not properly installed. With the magnification and strong backlighting in the first image this is easy to see. With the electrical components having no physical contact with the heat sink even a low power use could damage or destroy the power converter. This may be the cause of many of the negative reviews of this device. It is a good example of how just tightening screws out of order can have significant impacts on product life. Two of the modules received suffer from this manufacturing defect in varying degrees. It is detectable without any disassembly by just carefully examining the heat sink for tilt. Look closely and you will see the heat sink has a slight but noticeable tilt. This is how two of mine arrived right out of the box. If you are interested in my applications, construction details, justifications, and comments about the module then please read on. I needed a new dew prevention heater strip controller. All the ones I could find were very over priced, feature poor, single purpose, and based on PWM(Pulse Width Modulation) technology. I know that many people praise PWM for dew heater control without realizing the consequences. Often touted as 97% efficient they dominate the market with some units selling for as much as $370 dollars. I greatly prefer just simple voltage or current regulation like in the XY-SK35. And it is true that a PWM may be very efficient, however hidden in that efficiency may lurk high levels of Radio Frequency Interference(RFI). I have heard the harmonic RFI interference from these PWM dew heaters on the AM radio in my car from two miles away. Some PWM dew controller manufacturers brag about shielded cables. A shield isn't a shield unless it is grounded. Preferably on both ends of the shielding. A ungrounded shield usually goes by another name. A antenna. I don't see how such devices can even be legal In the U.S.A. I scanned the XY-SK35 power converted module, properly cased and grounded, for RFI with a spectrum analyzer from 130 to 560 kilohertz and I could find no signals above a -78db background at one meter when providing a 12 volt 2 amp output. I could find no interference in the AM radio band. It seems that most of the 185Khz switch energy of the XY-SK35 ends up in the heat sink instead of being broadcasted. Since it is a true power converter I can also use it with solar panels, AGM batteries, and wind generators to power just about any dc device. With such universal utility the XY-SK35 is extremely cost effective. The XY-SK35 has so many adjustable limits that you can not only power many devices, you can do it safely. Backflow prevention in the native electrical design is a nice feature. It even has a lock out function to keep your devices safe from the curious, children, and the occasional evil do'er. I made my 3 channel power converter with multi-pin connectors so I can make various input output wiring harnesses as the need arises. I also put in red filters to cut the blue light that kills night vision. The XY-SK35 does have a bright beautiful display, however it was just too bright for some of my purposes. I made up heat conduction blocks to replace the heat sinks and conduct heat to the aluminum case. I find fans make too much noise, cause too much contamination accumulation, and are not a good idea for electronics in moisture condensing environments. I even put in a 1/4 -20 UNC thread mount since I have a lot of old unique camera mounting fixtures so I can mount my power converter just about anywhere. I still gave the XY-SK35 power converters 5 stars because even though they have manufacturing issues, since I was replacing the heat sinks anyway, they did not affect me. And I still have all of the protection features and the lack of RFI that I find valuable. I attached various images to show my implementation, utilization, and construction methods. Keep on making!