SV503 80ED telescope's objective lens features an S FPL-51 extra-low dispersion glass ED element and FMC coating, which effectively eliminates chromatic aberration. This results brings you images with true colors and high contrast.SV165 Mini Guide Scope Support sensitive auto guiding cameras for easy guide star acquisition.Is it inconvenient to carry OTA? Have a little trouble going out? SV211 handle bar is the solution to travel problems. It is suitable for close handling and protects OTA from damage. At the same time, it can also be used as a general dovetail, suitable for installing all SVBONY guide scopes and finder scopes, especially designed for SV198 guide scopes, which are perfectly matched and enriched in use.SVBONY Universal Dovetail Base is compatible with finder scope; can be installed on telescope; Compatible for Clestron Orion Sky-watcher Vixen and so on.