B-LINE / ruler

L-LINE is a ruler for people who is visually impairable.
They can use this item for taking measurement of stuffs or drawing something.
When they use a normal braille ruler, it is hard to take and check the correct measurement as there is no device or function without braille on the ruler itself.
L-LINE is invented to cover the existing problem by cutting grooves on the ruler to help to check the measurement that users want to take and solve drawbacks.
It is more convenient and accurate than normal ruler to use to adopt method that moves along grooves on the ruler.