4 x 7" boxed set released in a numbered limited edition

Disc 1 pressed in marbled grey vinyl. (Sound source: metal.)
Disc 2 pressed in red vinyl. (Sound source: heartbeat.)
Disc 3 pressed in luminous vinyl. (Sound source: glow & fluorescent lamps.)
Disc 4 pressed in blue vinyl. (Sound source: water.)
Contains a 7"-size insert for each record