[Stefan Buda]

Good quality 3D printed Bahtinov masks for telephoto lens. Slits are 2mm wide, so they are suitable for focal lengths of over 200mm. The smaller one fits 67mm thread size and the larger one is for 72mm thread. They are slight push fit, no need to mess with screwing them in.
The red rim is for red torch visibility.
If there is demand I can make these for all sizes up to about 140mm clear aperture.
You can have these for $30 or I can separate them for $20 each. If you are not from Melbourne and can't pick up then a $5 postage charge aplies too.

Update: The size 72 is sold, the 67 is available for $20.