Review on Enhance Your UNO R3 with the HiLetgo 5V 4 Channel Relay Shield: Efficiently Control Four Channels by Mike Ken

You definitely get what you pay for here. First, they are shipped in a padded envelope so you can imagine what the pins and plugs looked like after UPS/FedEx/USPS got their hands on them. Luckily I was able to straighten them without breaking them, which was a trick because the contacts are softer than regular connector pins. Second, the terminal block pins for Relay 1 make contact with the USB chassis and tie the NO, NC, and COM pins together. Third, half of the terminal block contacts weren't even soldered to the board. After I fixed everything, everything turned out to work fine, time will tell.