SVBONY 1.25" 2X Barlow Lens Doubles The Magnification Multi Coated Broadband Green Film with M42 Thread for Standard Telescope Eyepiece Astronomy The value must have 2x barlow lens doubles the magnification of any 1.25 inch eyepiece;double the capacity of an existing set eyepieces at the cost of a single eyepiece The apochromatic barlow lens provide a high power magnification allow you look more closely and more detailed at the moon's surface and other planet 2 element one group broadband green film multi coated optical glass;the housing is blackened to maximize image contrast;both that gets high quality observation without additional chromatic aberration;make image more crisp and sharp Quality aluminum stock and black anodized body with M42x0.75mm thread;work as a t adapter;connect DSLR or SLR camera to telescope easily via a separate sale t ring adapter Connect DSLR SLR camera to telescope easily;the T ring adapter you buy separately depending on the model of camera