1/2 in. x 1/2 in. Brass Sprinkler Extension (12.7 x 12.7 mm) is machined from a single piece of solid brass to extend the distance between a fire sprinkler's thread connection and sprinkler system piping. Used when a drop nipple has been cut too short or to accommodate variations in drop ceiling height, this extender features a 1/2 in. (12.7 mm) female NPT connection, a 1/2 in. (12.7 mm) male NPT connection, and is 1/2 in. (12.7 mm) long.
Based on the specs in the description of the product, I had thought I was receiving a 1/2" X 1/2" extension that was 0.62" in length. When I received the fitting it was 1" in length. Although I was able to make this work with some minor modifications, the 0.62" inch fitting would have worked perfectly.