Billiard eyeglass, has upper and lower pairs of lenses, and two-piece connector fastened in center of stud to firmly connect lower and middle parts, where upper pair of the lenses is rotatable around axis of stud or groove
摘要
<p>The glass has upper and lower pairs of lenses, and a two-piece connector fastened in a center of a stud to firmly connect lower and middle parts. A groove is centrically tapped at the stud by screws with a locknut. The middle part is centrically clamped to another groove. The upper pair of the lenses is rotatable around an axis of the stud or the latter groove. Edges of the lenses are smoothed to form a small gap between the lenses.</p>
