Rulers by Père Alex & Marchand de trucs

See Video Below:

Description:
 

This classic illusion, made famous by psychologist Joseph Jastrow, is elegantly revisited here by Father Alex.
 
 The magician presents two wooden school rulers: one marked in centimeters, the other marked in inches.
 
 He explains that the imperial system is decidedly mysterious for a French person... and immediately proves it:
 
 Placed side by side, 15 cm seem to be equal to 6 inches.
 
 By simply reversing the position of the rulers, not only do they visually change in size, but this time 7 inches appear to correspond to 9 cm.
 
 To conclude, the magician reveals that the two rulers are in fact exactly the same length.
 
 A strong, clear, and immediate visual illusion that never fails to surprise and delight.
 
 Contents
 
 A beautiful wooden box, specially crafted for this effect
 
 Two wooden rulers: one marked in centimeters, one marked in inches
 
 An instructional video in French, in which Father Alex explains the principle behind the trick