1.25" 3X Focal Extender 18-4mm-eye-relief but they relax the eye

but they relax the eye so the observer could pay attention to subtle details for extended periods

intuitive navigation of the sky

combined with protective rubber armoring

a neck strap

which results in a wider field of view

1.25" 3X Focal Extender 18-4mm-eye-relief but they relax the eyeA good Focal Extender adds some real versatility to your telescope accessory line up. First of all, it allows you to increase the magnification of any eyepiece with the same barrel size that you already own. In other words, 3 eyepieces offer 6 magnification choices with the addition of a focal extender. Secondly, most of the time, lower magnification eyepieces have better eye relief than higher power models. When using a focal extender to increase