Precision 2.5x Magnification Boost: This 2.5x deluxe barlow lens delivers authentic 2.5x magnification without compromising edge-to-edge sharpness; perfect for capturing planet or lunar rille details at extended focal lengths Professional-Grade Multi-Coating System: Feature fully multi-coated apochromatic lens system with 4 elements design; effectively minimize chromatic aberration and ensure clear and sharp imaging performance; perfect for high-contrast planetary observation Engineered with Mutiple-Layer Material: Constructed from anodized aluminum provide using cycle and lightweight portability; Integrated with premium optical glass significantly enhance chromatic aberration correction and deliver exceptionally better image Double Adapter System: Functions as 2 inch to 1.25 inch adapter enable compatibility with 1.25" & 2" eyepiece as well as other telescope accessory of same diameter; equipped with precision CNC-machined brass compression ring and dual knurled thumbscrews 2 Inch Bottom-Mounted Design: This 2 inch telescope barlow lens includes 2" tube diatemer that connect to 2" telescope focusers or other 2" telescope accessories and M48x0.75 female thread to connect to 2" telescope filter with M48x0.75 male thread 2" Barlow inserts between the eyepiece and a 2" eyepiece holder on the telescope and increases the magnification by 2.5x. It can be used with 1.25" eyepiece and 2" eyepieces. The 4-element fully multicoated lens assembly offers superb field flatness and minimal chromatic aberration.