Holy cow. I can't believe how lucky I was to have found this place!
I think the majority of their business is mail-order driven, but the retail location is PHENOMENAL. You enter through what appears to be their offices and go through a side door into the warehouse area.
It's a good idea to have a copy of their catalog and some item numbers ready to go before entering. There isn't too much to window shop in the warehouse. All the staff members are very knowledgeable about everything they have there. I asked a random staff member about where I could find a certain item number and he replied with "oh, the auto pet barrier?". I was stunned that he knew what it was off the top of his head. The place is HUGE.
I wish they carried food though...