Flats
Arbiter Flats use the same Autotune AT system as the maple AT kits, but have no shells, making them very compact and portable as well as quiet. They became very popular during the 'unplugged' craze of a few years ago. I saw Rob Townsend playing them with The Blues Band in an unplugged set.
They are still manufactured and selling very well.
There have been several versions, the latest being the "Flats Lite" which use a lot of ABS plastic to make them both light weight and low cost portable kits.
I don't need to say much more here since the drums are currently available, best to go straight to Arbiter at this point, I think...