The Fleshlight (talking about an actual Fleshlight, not just any generic masturbation sleeve) has a screw-on cap on the end, which can be tightened or loosened to let more or less air through during use.

If the cap is closed, then during use air can go out but has a harder time getting back in. This means that when pulling out on strokes, a feeling of a tighter, vacuum-packed snugness is created.

It’s a good feeling, but the cap on the Fleshlight isn’t the best and overall this feature doesn’t work as well as it could.

When I shared my simple Fleshlight mod for tightness on Reddit, a user mentioned that the exhale valve from a dust mask could be used for a much better airlock, but it required drilling a hole into the Fleshlight’s end cap and using some glue.

Here is a non-destructive mod to get all the benefits of an improved airlock without the need to drill anything, and probably not need any glue. Just get a disposable dust mask with an exhalation valve, and 3D print the part shown below (download link at the end of this article.)

Below is a gallery showing the process. Basically:

• Buy a disposable dust mask with a one-way exhale valve. (Air is easy to go out, but can’t come in.)
• Peel the valve off the mask.
• 3D print the new part. Note: It doesn’t look like anything in particular, so it’s not embarrassing to have someone else print it if needed.
• If the valve fits, then just push it through the hole. It should press-fit snugly into place. All the ones I tested fit perfectly but if yours does not, you can glue the valve over the hole instead. Hot glue should work fine.
• Screw the new cap (with valve) onto the Fleshlight instead of the normal end cap.
• The new cap (if snug) will allow air out easily, but won’t let air back in. This means the sleeve will hug an erect penis much better than with the factory cap.

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Click here to download the 3D model.