These represent a line of Pendant Light fixtures that we've used for years. There are much fancier ones available, but these have worked well and have been in steady supply.
They come with the medium-base socket, so are compatible with both our Fluted Shades and Straight Shades (Note: although the Large Shades have the same size opening, their weight can exceed the capacity of these fixtures, so are not recommended). The kits come with everything shown in the photos. The cords are a little over 4' in length, and are adjustable.