1 Muffler Hatch LV +
1 Upgraded Pollution Scrubber

1 Muffler Hatch MV +
1 Advanced Pollution Scrubber

1 Muffler Hatch HV +
1 Precision Pollution Scrubber

1 Muffler Hatch EV +
1 Air Recycler

1 Muffler Hatch IV +
1 Upgraded Air Recycler

1 Muffler Hatch LUV +
1 Advanced Air Recycler

1 Muffler Hatch ZPM +
1 Precision Air Recycler

1 Muffler Hatch UV +
1 Atmospheric Cleaner

1 Muffler Hatch UHV +
1 Biosphere Cleanser