Svbony SV135 zoom eyepiece allows you to change magnification power without swapping out eyepieces 7-Elements/4-groups made of high index glass deliver sharp, high contrast vistas A simple twist of the zoom eyepiece housing changes the focal length from 7mm to 21mm, providing a variety of viewing magnification powers Sleek black barrel with safety undercut to reduce the possibility of the eyepiece slipping out of the focuser or diagonal Blackened lens edges, anti-reflection threads for maximum contrast
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