Stealth your 901

[JustPuffin]

If you want to be inconspicuous take a Paper Mate pen cap and slide it over the LED. Fits great and has a white plastic x at the top that works great for air flow. You’ll find it handy for storing in your shirt pocket or do what I do and slide it over your third button down inside your shirt. If it slips out of the pen cap you won’t lose it. Providing you have your shirt tucked in.

[e-pipeman]

Excellent. It would be handy if a black non-illuminating battery end-cap was available imho.

[Frankie]

I think a cap without the cross should do, too. The air should be flowing into the atomizer through the pinhole in the side.