|Overall Size:|| 4.0 in. x 4.0 in. |
(101.4mm x 101.4mm)
|Resolution:|| 20 and 40 cy/mm|
|Based on:|| ANSI/ISEA Z87.1-2015|
The ANSI/ISEA Z87.1-2015 Test Resolution Standard is described in the American National Standard for Occupational and Educational Personal Eye and Face Protection Devices ANSI / ISEA Z87.1-2015 documentation approved by the American National Standard Institute, Inc. on May 28, 2015. in the section 9.4 (page 18 and 19) “Refractive Power, Astigmatism and Resolving Power Tests".