890300 -890 Drying Tube, 300 mL/min, 4/pk

They're just a bad value vs. buying bulk desiccant and Bel Art reusable tubes.

These do a good job, but would be better in a laboratory setting as opposed to field setting with raw gasses and environmental humidity levels. Saturates quickly in the field. Save this item for use with gasses already filtered and dessicated. It does not come with the fittings needed to integrate it into an existing piping system.

Exactly what I expected.