ZF-9A Step Density Film

Features:

1. The blackness of the ZF-9A step density film can reach 5.0D and meet the ASME standard;

2. 9 test holes, error≦±0.05;

3. This step density film is a step density film that is uniformly verified by the Chinese Institute of Metrology. A set includes: a step density film and a verification report issued by the Chinese Academy of Metrology.