Clear and crisp image: FMC(fully multied coating) green film can reduce the reflection and refraction of light and enhance the transmission of light; 5Lenses in 3 Groups:Multiple group lens combination to improve optical performance, and delivers sharp images with good color correction and contrast; --Blackened lens edges and internally blackened eyepiece barrel to avoid internal reflection and provide a crisp image. Lens with different focal lengths and different structural designs that ensure you have a clear and crisp image , and a perfect observation experience. 20mm focal length fit for observing the lunar surface planets binaries and bright nebula interior,especially for deep sky targets. The barlow lens has a magnification of 5X, which can magnify the image without the Barlow lens by 5X, allowing you to see the craters on the moon with a low power eyepiece, making observation more comfortable. If you have a 30mm eyepiece paired with a 5X Barlow lens, you can get 6mm of magnification. Crisp and clear image. FMC (multi coated) 2 group lenses can increase the transmission of light and make image more crisp and sharp. Internally blackened barrel to avoid internal reflection and maximize contrast.