The air holes are inside above the
threads on the penstyle attys, but are usually small and hard to see.
Most have 4 little holes. Some are elongated and more of a tiny cut out at the top rim of the
threads rather than a hole and you have to have a good magnification and light to see them. Great atty... I use the RN4072 and 302 penstyles 90% of the time.