Wayne Limited- Group Delay Filter????

What is this thing? It was thrown in with a group of components I purchased from a retired professor. I had it hooked up for a while and could not tell the difference between the filter being on or switched to bypass. Does anyone know about this device? Should I give it another try?
I believe they were used in recording, for one application, to ensure the signals from different channels would reach the tape with the same time delay, so that all sounds in sync. Hopefully, someone who used one before will chime in. If you play one speaker through this, and send the same signal to another speaker you may hear the delay.
Thanks Dan, any idea if there is a market for something like this? I don't do any recording on my system. I may just unload it.
HI Pat,

this may only be test equipment being as it came from a prof. I doubt you'll find much use for it in your system unless you get into building speakers and stuff. But even then, there is so much available in pc software that I don't know if it has much value. Maybe check the DIY forums?