Reduction scale rulers

Reduction scale rulers - white, polysterene, 2 coloured grooves, 30 cm

1630 - “Engineer”
1631 - “Architect 1”
1632 - “Architect 2”
1633 - “parts to inch”
1634 - “arch. inches to foot”
1635 - “Vocational school”
1636 - “Surveyor”
1637 - “Surveyor 2”
1638 - “ISO divisions”