Astrozap focusing caps with integrated Bahtinov focusing wheelUnlike a simple Hartman or Bahtinov mask, the Astrozap focusing cap is a multi-purpose tool which allows for quick 'shutter-like' operation. Just turn the wheel to the open position for focusing, and then turn it again to the closed position to keep the dust out, or to image dark frames with your CCD or DSLR camera.The focusing wheel can be easily removed and replaced with an off-axis wheel for off-axis viewing, or an off-axis solar filter wheel for solar viewing on larger telescopes.Simply turn the thumbscrew to the open position, and turn to close. No plastic plugs required, and no tools needed. Made from lightweight aluminum and powder-coated texture black. Integrated Bahtinov focusing wheel. Allows for quick shutter-like operation. Turn wheel for open or closed positioning. Focusing wheel is easily replaced for off-axis viewing. Made of lightweight aluminum; no plugs or tools required.
Product Title: AstroZap Focusing Cap with Bahtinov Wheel