More magnification for existing eyepieces to see the details of moon and bands of Jupiter clearly;the Barlow lens is a must Quality and value 5x Barlow lens to give a big magnification boost to any 1.25 inch eyepiece It will help double the capacity of an existing set eyepieces at the cost of a single eyepiece;It's super easy to use;you can simply insert eyepiece of into the Barlow lens;then insert it into the scope Barlow lens could also more magnification without reducing the exit hole on the eyepiece Even a well made Barlow will little damage on the imaging quality size:31.7*65mm Material:Aluminum alloy colour:black Package Contents: 1 * 5X Barlow Lens Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.