About
For those critical measurements longer than 20" (500 mm), the optical scale extension adds a 20" artifact to increase your precision measurement length up to 40".
The optical scale extension uses a magnetic base to securely mount the invar extension bar and a scale holder from which the precision optical scale extends. Optical scales are sold separately in 5", 10" and 20" and 130 mm, 250 mm and 500 mm lengths.
For those critical measurements longer than 20" (500 mm), the optical scale extension adds a 20" artifact to increase your precision measurement length up to 40".
The optical scale extension uses a magnetic base to securely mount the invar extension bar and a scale holder from which the precision optical scale extends. Optical scales are sold separately in 5", 10" and 20" and 130 mm, 250 mm and 500 mm lengths.