I bought these to add an extra tier to my K&M 18950 and these couldn't be simpler to use - just slot them into the main stand, fixing them into place and then set your height and angle.
You can also adjust how far forward they extend over your existing keyboard, so you can have the upper one further back, to allow easier access to any surface controls.
The ends have a rubber-capped stopper, so your keyboard won't slip off if you have it tipping down at an angle.
Pros:
- a simple method of expanding storage for your keyboards
- sturdy
- easy to assemble.
Cons:
- none, really!