ZWO PROTECTING WINDOW Filter Type:AR Ø21mm the mirror-flop (or lens flop)

the mirror-flop (or lens flop) of the telescope optics

telescope and mount flexure and so on

The optional Sky-Watcher f/5 coma corrector delivers excellent correction

SWP3001-OTA

The SkyWatcher tripod extension for HEQ5 is a necessary accessory when you use a long refractor with your mount

ZWO PROTECTING WINDOW Filter Type:AR Ø21mm the mirror-flop (or lens flop)AR Protecting Window ZWO D21 AR Protecting window Technical Parameter: Diameter: 21mm Type: AR window Thickness: 1. 1mm Flatness: 1 4 Protects the sensor from dust and humidity. Match Model: The cameras that come with the D21*1. 1mm AR protecting window are listed as below: ASI120MM S, ASI224MC, ASI385MC, ASI290MC MM, ASI290MINI, ASI178MM, ASI120MINI. ZWO D25 AR Protecting window Technical Parameter: Diameter: 25mm Type: AR window Thickness: 1. 1mm