Simple light shelf. It is epecially designed in combination with wooden sticks of 3x22 mm. 

CZ: jedná se o zednickou lať, kterou lze levně koupit ve všech stavebninách.

Those wooden sticks are light, cheap and it can be bought in all the builders shops in the Czech Rep.

Fits perfect, not any screws or glue necessary.

You can use just 2 holders or more in row if you use longer sticks.

I can change dimensions for you, if you need it for some specific sticks in your country.