The price is negotiable
A two-position instrument that uses a fixed-size image and doubled, adjustable object size to determine the radius of curvature of the reflecting surface
The instrument uses two self-luminous sights (object), the first in the form of a red field and the second in the form of a scaled green pattern, which are represented on a graduated arc track to maintain a constant distance from the eye
Two color filters
Movable base
Graduation in the range of 0-180 degrees
No power supply included
