William Optics Flattener 4 – 0.8X Reducer
http://www.aliexpress.com/item/Sky-Watcher-0-85x-Focal-Reducer-And-Field-Flattener-For-100-900mm-ED-Refractor/1439912469.html
William Optics Flattener 4 – 0.8X Reducer
http://www.aliexpress.com/item/Sky-Watcher-0-85x-Focal-Reducer-And-Field-Flattener-For-100-900mm-ED-Refractor/1439912469.html