Yoked Prism Frame with 360 Degree Compass and Adjustable Nose Piece608700
These Yoked Prism Frames come with an elastic string and are available in 2 lens sizes: 38 mm for pediatrics and 48 mm for adults. These frames also come with a soft adjustable nose piece. Large thumbscrews are on each side so that each prism can be secured.
The 360° compass or protractor helps to position the prism base.