These are oculars from German and Nato military-design, spotters and binoculars, five in total.
Erfle wide-angle long eye-relief oculars. All are coated 4-5 element and have helical focusers. 16-21mm focal length.
Excellent contrast , sharpness and edge-correction. You simply have to make the 1.25" barrels from 1.25" aluminum stock.
Finely machined brass, steel and aluminum cells.
Excellent project for a cloudy night.
$59 for all five. shipping included. Paypal +2%