Astro Basics 6mm Standard Eyepiece RRP £13.99 Save over 40% with Buy It Now + Free UK Postage. Supplied with Storage Case Fully Coated - Standard 1.25" (31.77mm) Fitting Astro Basics standard eyepieces provide excellent value for money for beginners Supplied in protective storage case. Features: 1.25" (31.7mm) barrel fits any telescope with a standard 1.25 inch fitting. Threaded to accept 1.25" filters Fully coated optics Eyepiece appearance may vary slightly as shown in images This listing is for one 6mm eyepiece only - group image to show varying design (4mm, 6mm, 12mm and 20mm sizes in the Astro Basics range) What Magnification is this Eyepiece? The magnification produced by an eyepiece depends on the optical system it is used in. In a standard astronomical telescope the magnification is found by dividing the focal length of the main tube by that of the eyepiece. For example, a 1000mm scope tube used with a 10mm eyepiece gives 1000/10 = 100x magnification. Used with a 5mm eyepiece gives 1000/5 = 200x.