This terminal block appears to work fine in all the ways it's supposed to. Except that the body is extremely easy to crack. Just the force required to unscrew one of the terminals caused the body to crack in each of the two blocks I purchased.

This is the first time I have felt compelled to write a negative review of a Sparkfun product, as they tend to carry quality products. I bought this item because it looks very clean and sturdy from the photo and was planning on using it in a project I wanted to look professional and clean. The clear plastic cover came with multiple scratches on it and the numbers 4-6 were not stamped into the plastic hard enough and were hard to read. The "600V 15A 6P" label on the cover that you can easily see in the photo was non-existent. To make it look even worse, there were pits in the side of the clear plastic cover from where they were broken apart after being molded. The screw terminals seem fine, but the black plastic body is poor quality plastic and easily cracks, as another customer mentioned. I believe it is priced fairly for the quality, but the picture is misleading. This would work fine in a project if you don't care how it looks and are very gentle with it, I would not use it in a project where you want to frequently change connections, as I don't think this will last very long. I don't know what perfect version of the product they used for the product photo, but it is not what I received.