These premium-quality eyepieces increase the magnification of the Oberwerk BT-70-45 and BT-100-45 binocular telescopes. Available in 3 focal lengths (16mm, 12mm, 8mm) that give 1.5x, 2x, and 3x the magnification of the stock 23.9mm BT eyepieces. They have precision adjustable twist-up rubber eyecups, a wide 65° AFOV, with excellent sharpness to the edge of the field. The barrels are threaded to accept 1.25″ filters. Sold in pairs.