This is a replacement ceramic atomizer for the Cloud Penz Vaporizer. They feature a ceramic base and an all-ceramic bowl for vaporizing your favorites waxes. The A1.0 and A2.0 version utilize ceramic rods inside the heating chamber, whereas the A3.0 version uses two metal coils. Atomizer Compatibility: The original Cloud Pen is only compatible with 'Original Series' atomizers. The newer 'Click Series' atomizers will not work with the original Cloud Pen. Cloud Pen versions 1.0, 2.0 and 3.0 are only compatible with 'Click Series' atomizers. The 'Original Series' atomizers will not work with these models.