Sky Watcher Quattro Coma Corrector Black. Magnification remains unaltered. Specifications for Sky Watcher Quattro Coma Corrector: Manufacturer: Sky Watcher Color: Black Features of Sky Watcher Quattro Coma Corrector: f/4 ED coma corrector. FPL51 and Schott glass. Optimized for Quattro imaging Newtonian telecscopes. Requires 55mm backfocus. Package Contents: Sky Watcher Quattro Coma Corrector Telescope Sky Watcher Quattro Coma Corrector Black S20204