Were shattering rulers ever a real concern? Seen this warning/claim since school but never seen the cause/effect of a non Shatterproof ruler.. : r/pics
Helix White Shatter Resistant Ruler 15cm/150mm Pk50
6" White Shatter Resistant Ruler - Pack Of 50 from £8.57
Classmates Shatter Resistant Ruler White 300mm/30cm - Pack of 10