Shinwa H-101A 150 mm Rigid (15 mm x 0.5 mm) Zero Glare Satin Chrome Stainless Steel Machinist Engineer Ruler / Rule with Graduations in mm and .5 mm - Construction Rulers - Amazon.com
How Big Is 5 Millimeters (MM)? – Measuring Stuff
Plexiglas lead ruler graduated every 5mm - marked every 1cm