This cable manager is there to lay the cables nicely at the table, for example.

It is best to use double-sided adhesive tape for fastening.

You need a piece of filament (1.75mm) to join them together. Insert the filament into the hole on the hinge and heat it with a lighter on one side and press it flat. Shorten the filament on the other side so that it fits. Heat the other side and press the filament flat.  

Dimensions (3 cables): 
Holes: 8mm diameter
Length: 44mm
width: 25mm
Height: 10mm

Dimensions (5 cables): 
Holes: 8mm diameter
Length: 64mm
Width: 25mm
Height: 10mm