Step back into Earth’s deep past with the 35% Oxygen: Carboniferous T-Shirt, inspired by the prehistoric atmosphere of the late Paleozoic Era. Featuring a giant dragonfly (Meganeura)—a product of hyperoxygenated air during the Carboniferous Period (approx. 359–299 million years ago)—this design celebrates a time when towering lycopsids, vast coal forests, and massive arthropods dominated Earth’s lush wetlands.

Printed on eco-friendly material and designed to spark curiosity, this shirt is more than fashion—it’s a fossil-era statement about our planet’s atmospheric evolution. Every order funds kelp restoration on the Pacific Northwest coast.