Single Pass Front Mount Etalon System. 50mm aperture (no central obstruction) integrally tuned etalon for use on any customer supplied refractor. System includes  the B600 blocking filter standard which provides full disk images on telescopes up to 600mm focal length. Larger blocking filters suitable for longer focal length telescopes are also available options.

Single Pass Front Mount Etalon System. LS75 Hydrogen-alpha system - 75mm aperture (no central obstruction) integrally tuned etalon for use on any customer supplied refractor. System includes  the B600 blocking filter standard which provides full disk images on telescopes up to 600mm focal length. Larger blocking filters suitable for longer focal length telescopes are also available options.

Single Pass Front Mount Etalon System (Patent Pending Design). LS100 Hydrogen-alpha system - 100mm aperture integrally tuned etalon for use on any customer supplied refractor. System includes the B1200 standard for use on telescopes up to 1200mm focal length.

Single Pass 160mm Front Mount Etalon System (Patent Pending Design). LS160 Hydrogen-alpha system - 160mm aperture  integrally tuned etalon for use on any customer supplied refractor. System includes the B1200 standard for use on telescopes up to 1200mm focal length.