Very good condition, really solid build with quality matte black finish, sounds great. Bass mod changes the input and coupling capacitors from standard values to allow more bass frequencies to pass through the distortion stage.
Light studio use only and from a smoke free environment. You can see more details on the design of the original pedal, on which this is based here https://www.earthquakerdevices.com/blog-posts/sunn-o-life-pedal