Precise Strabismus Measurement:Designed for accurate phoria and strabismus testing with direct AC/A ratio measurement. Adjustable Height:Features a height adjustment from 31cm to 41cm, ensuring a comfortable position for users. No Conversion Required:Eliminates the need for additional conversions, providing direct strabismus prism measurements. Professional Ophthalmic Tool:Ideal for optometry and ophthalmology practices, offering reliable diagnostic assessments. Compact and Portable: and easy to transport, this vision tester is perfect for both in-office and field use. Color: White Material: plastic Package Contents: 1 x Phoria Strabismus AC/A Test Tool(Printing ) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.