I wish that I installed this secondary ADAHRS when I installed the first. My top skin was not installed and I could just put my hands on it standing next to the aircraft. Since I installed the top skin I kept thinking about the secondary unit. This meant that I had to crawl back in the empennage and work in cramped quarters. My brother came over and assisted me by handing me all of the tools and fittings that I forgot. He kept me from having to crawl in and out many times. Thanks Charles.