Yoked Prism Frame with 360° Compass

Yoked Prism Frames with elastic string are available in 2 lens sizes: 38 mm for Pediatrics, 45 mm for VTE (Italy) lenses and 48 mm for adults. Comes with large thumb screw on each side so that each prism can be secured.

A 360° compass or protractor which helps to accurately position the prism base.