Rackstuds™ Series II DUO, the NEW 1RU Rack Mount Solution in 19" Racks with Square Punched Vertical Rails, 50pcs/Pack

Pros:
1) No tools needed, easy to install and remove
2) Pins helps a lot then mounting hardware where you need to hold it
3) Pin is in the middle of square hole making you sure if you left one unit between two used - it's enough space and hardware not slightly shifted up or down
4) Lightweight (if you need to carry them in backpack)
Cons:
1) Not fit in some racks (need some tool to push it harder)
2) Three parts instead of standard two, yellow fixate easy to drop and loose
3) Expensive

It's easy to install and hold the devices steadily.
But the instruction manual on the back of packages is not kind enough, it's missing some tips such as the direction of yellow parts.
I hope the manual improved or paste links to instruction movie.

Rackstuds are the real replacement to traditional cagenuts. Highly recommended.