Replica grating PTG-1
600 lines/mm on 25x25mm ruled area on a 50 X 50 mm glass. (Shown at bottom of picture as a flat square. All four types are shown.)
Forensics Lab Supply Number 3178001.
Formerly Grau-Hall Corporation dba Grau-Hall Scientific.
Purchase orders may be sent by email to staff @ grauhall.com or by FAX to 916 379 9639 or by mail to P. O. Box 279592, Sacramento, CA 95827-9592.
All products shipped from Wabash, Indiana.