When inserted between the eyepiece and telescope, this x-cel 2x Barlow lens doubles the magnification of all your 1. 25" Eyepieces. The premium apochromatic optics yield High contrast, sharp images, virtually free of false color. The Black anodized housing with orange highlights matches the eyepieces in the Celestron x-cel LX line. A centralized rubber grip helps to keep your hands securely on the barrel, even when your fingers are cold or you are wearing gloves. A brass compression ring just inside the top of the x-cel Barlow grabs your eyepiece gently but firmly when you turn the thumbscrew. Once the thumbscrew has been secured in place, the brass ring keeps your eyepiece in the Barlow instead of relying on the tip of the thumbscrew itself, offering a better grip and protecting the barrel from scratches. The barrel of the Celestron x-cel LX 2x Barlow is threaded to accept 1. 25" Filters, allowing you to change eyepieces without removing and re-attaching the filter from each eyepiece barrel.