Introducing octagonal IHADA brass knobs.
They come in a combination of two sizes x 3 screw length:
Knob Octagon L with 20mm screw (KNH-L-20)
Knob Octagon L with 25mm screw (KNH-L-25)
Knob Octagon L with 30mm screw (KNH-L-30)
Knob Octagon S with 20mm screw (KNH-S-20)
Knob Octagon S with 25mm screw (KNH-S-25)
Knob Octagon S with 30mm screw (KNH-S-30)
You can choose an appropriate one according to the wood piece's size and thickness onto which you desire to install the knob. The knob can be fixed at the desired position using the screw attached from the other side of the wood piece onto which the knob is installed.