The 10mm and 20mm series small-caliber double cemented objectives, specially designed for astronomy enthusiasts, are core accessory lenses that enhance the observation performance of astronomical telescopes, providing a clear and sharp visual experience for starry sky exploration.​ This series of lenses is meticulously crafted using professional double cementing technology. By precisely cementing two pieces of optical glass of different materials, it effectively eliminates chromatic aberration and spherical aberration, making the edges of observed celestial bodies clearer and details more abundant. The two specifications of 10mm and 20mm cover different observation needs. The small-caliber design ensures portability while possessing excellent light-gathering capability, enabling it to present relatively pure starry sky images even in urban light-polluted environments.​ As highly adaptable accessory lenses for astronomical telescopes, they are compatible with most mainstream small-caliber astronomical telescope models. The installation process is simple and convenient, allowing them to be put into use without complex debugging. Whether for entry-level astronomy enthusiasts observing near celestial bodies such as the moon and planets, or advanced users recording starry sky details, this double cemented objective can rely on its stable optical performance to help users capture the charm of the bright galaxy, making every observation full of exploration surprises.