This telescope eyepiece adapter is made of , which can withstand long-lasting use. Features the aluminum material, which has high durability, not easy to deform. Fine workmanship, ensures practicality. Features -Color: Black -Material: aluminum -Size: 4.50X4.50X4.50cm/1.77X1.77X1.77in Connector size: 0.965 inches outside diameter (suitable for 24.5mm interface) Interface size: inner diameter 1.25 inches (suitable for 31.7mm eyepieces) - The inside of the adapter is fully threaded to minimize reflections. - The extension tube provides the extra focal length "return" that is usually required for short-range ground observations or astrophotography applications through a telescope. - Use this extension tube to obtain the correct image scale or the precise spacing required by the reducer or field flattener. - It is in stable characteristics, high performance and it is in great reliability, simple, easy to use. - It is simple in design, but very practical in use, which brings great convenience to you. Package list: 1 x eyepiece adapter