Pentax XF 8.5 Eyepiece 1.25 Tube. 5 Eyepiece 70531 featuring a bright high-contrast image an American-standard 31.7mm sleeve and focal lengths ideal for outdoor viewing and bird watching. With a focal length of 8.5 mm the high-performance PENTAX XF8.5 eyepiece is ideal for outdoor viewing and bird watching. As a standard Unifocal Eyepiece it offers a 60 degree apparent field of view long eye relief and bright high-contrast images. Specifications for XF Pentax 8.5mm Eyepiece: Magnification: 46x Focal Length: 8.5mm Apparent Field of View: 60 degrees Eye Relief: 18mm Package Contents: Pentax XF 8.5 Eyepiece Specifications for Pentax XF 8.5 Eyepiece: Manufacturer: Pentax Weight: 150 g Features of Pentax XF 8.5 Eyepiece With JIS Class 4 weatherproof construction the XF eyepieces are more durable and water resistant. With a focal length of 8.5mm the high-performance PENTAX XF 8.5 eyepiece is ideal for outdoor viewing and bird watching. It is also recommended for use with astronomical telescopes with 1 1/4" focuser. As a standard unifocal eyepiece it offers long eye relief and bright high-contrast images. The rotatable eyecup offers an adaptor-mounting screw/thread when removed (single-focus models: 30.5mm in diameter with a 0.5mm pitch; zoom: 43mm in diameter with a 0.75mm pitch). Compatible with the following: PF-65 and PF-65ED(A)II series spotting scopes PF-80 series spotting scopes PF-100 series spotting scopes. Package Contents: Pentax XF 8.5 Eyepiece Pentax 70531: XF 8.5 Eyepiece 1.25 Tube