Datyson 5P0087 Fine Thread Astronomical Telescope Accessories 1.25 inch 0.5X Defocusing Lens Reducer(Black) Features: 1.Increases imaging area 2.Nice anodized aluminum housing 3.Fits all standard 1.25" scope eyepieces 4.Optical lens helps transmit more light 5.Reduces your telescope focal ratio by 0.5 6.Can both have a filter attached and be threaded onto an eyepiece or camera 7.It is not recommended for very fast scopes or very wide angle eyepieces for visual 8.The reducer has standard 1.25" telescope threads M28.5x0.6 and fits onto the nose of any 1.25" eyepiece;diagonal;extender tube;camera adapter 9.Achieve even larger image fields with your telescope or camera when you attach an extension sleeve between the reducer and telescope or camera Parameter: 1. Magnification: 0.5X 2. Lens material: optical glass 3. Frame material: aluminum alloy 4. Appearance color: black 5. Thread specification: 5P0087 fine thread = M28x0.6mm 6. Interface size: 1.25 inches 7. Net weight: 12g 8. Gross weight: 16g 9. Product list: 1 reducer lens, 1 storage box