Eyepiece with different focal lengths and different structural designs that ensure you have a clear and crisp image , and a perfect observation experience 6/9/15/20mm eyepiece set Low;medium and high powered magnification for a wide range of viewing;enhance the visual experience Four focus length for your choice 6mm,9mm,15mm and 20mm.There are also have a eyepiece kit consists of those four focus length SV155 telescope filter set Red Orange Yellow Green Blue that meets you different needs. CPL Filter: It filters out scattered light, enables you to cut through reflections and see the detail behind it. It tones down the brightness of the lunar surface so you can enjoy optimized contrast of the moon. High magnification for eyepieces to see more details of the moon; bands of Jupiter clearly; SVBONY 2x barlow lens is a better choice.