I was not the end user but a first-time installer of Amcraft acoustical curtains. After a slow start, and many questions, our designer at Amcraft, James, answered all my emailed questions, within an hour that I sent them. The support and customer service were amazing even when I had to ask several questions in one day. The " threaded rod track system " with a stationary curtains and filler curtains were a very nice product to work with and after a getting the kinks out of the process, very easy to install.