The high-quality Sky-Watcher mirror in these star diagonals has been given a highly reflective dielectric coating in a special multiple coating process, so that it can transmit 99% of the incident light and thus enables particularly high brightness and contrast. (Normal mirror diagonals usually only reflect 90-95% of the light) Scope of delivery: 2″ 90° diagonal mirror Dielectric adapter to 1.25″ dust protection caps! Power supply and batteries are not included in the scope of delivery!