Lunt LS50FHa/B600d1 H-alpha solar filter Specifications:
Aperture: 50 mm
No central obstruction
Bandwidth: <0.75 Angstrom
Tuning: tiltable Etalon
Housing diameter: 95 mm
Length: 73 mm
Weight: 0.7 kg
Front thread: M90x1 female thread
Rear thread: M90x1 male thread
Blocking filter: B600 in diagonal for 1.25" focuser
Maximum focal length of telescope: 540 mm