Bahtinov focusing mask for an Orion 80ED (or similiar) telescope - it has an 80mm aperture, 16mm outer edge, and 2mm slots.
Note that this does not include any way to mount or otherwise hang the mask over your telescope objective. Alternatives include a sewing hoop, or simple foam blocks glued around the outer edge.
For more information, go to http://astrojargon.net
Material options and prices (All prices are in US$ and exclude shipping costs):This item is available in the following options:
3mm Black Acrylic
Made from black acrylic.
|$5.00||Buy this option|