I needed a keyboard holder for my secondary keyboard on my cockpit. After the first try I shifted it by 20deg towards me. It's designed to be mounted 25cm-s from each other (measured from the right side of both pieces). It's designed for a keyboard not taller, than 13,5 cm.
You're adviced to use some kind of anti-slippery stickers to prevent the keyboard from sliding sideways.
The author hasn't provided the model origin yet.