It's a 'reflective companion' to their recent album, Wonderland.
The cassette, out via their own DDS label, follows their most recent album, Wonderland, which was releaded back in November. Circulation is meant as a "reflective companion' to that one, according to the press release, and was "pieced together from breakdowns, transitions, pitched-down intros and transposed versions of music the pair have been influenced by over the years." It also features new edits by the UK duo. Circulation runs for about one hour and is limited to 400 copies.
Circulation is out now via DDS.