The CA-301 in line phase reverser serves one purpose: It simply switches the polarity of pins 2 and 3. Pin 2 is wired through to pin 3. Pin 3 is wired through to pin 2.
This is a professional grade adaptor, which is fully compatible with standard 3 pin XLR connections.
One screw each holds the male and female contact assemblies in the body.
The body is nickel silver finished steel. The female contact points are good quality spring steel.