LEA GRATINGS® are for preferential looking test situations with infants or children and adults with disabilities to determine detection acuity. Grating levels printed on each handle are: 0.25, 0.5, 1.0, 2.0, 4.0 and 8.0 cpcm (cycles per centimeter of surface).

Includes instructions and storage case.

4 paddles 8" (20 cm) in diameter.

https://leatest.com/sites/default/files/pdf/253300_GratingPaddle.pdf