Converter arrived in an antistatic bag. the bag is in the mail pupyrchatoy envelope. soldering quality and working are excellent.

Bought two devices. Nifty controller for moderate current requirements. I used it to drop 12VDC to 9V at 2 Amp and the switch got hot - well above 50C. Seemed to allow 1 Amp with no heat sinking and remained under 50 C. The switch IC uses 42 small (30mil?), copper foil dots on backside as a heatsink. You need to get a heatsink onto the device tab which is hard to do to run moderate current. The module is nice in that the quiescent current is about 5 mA.

This is a great product at a fantastic price! I have used the ones I purchased in many ways. It's a very convenient means of getting a well-regulated, stable 5v from a 12v battery, solar panel, or other source. It is handy for generating 3.3v, 5v, 12v, 15v, 24v, etc from unregulated supplies such as simple transformer/rectifier/filter designs or unregulated "wall-wart" packs. I have used it for controlling brightness of LEDs, controlling charge rate of batteries, speed control of small motor, etc, etc. The applications seem endless, and if you are an active experimenter, it's nice to have one or more on hand at all times! Note that the input voltage must be at least about 1.5v greater than the desired output!