These are our very popular gas assisted pop up shelves they are Very useful to put your phone on or a drink in your kombi or camper when out camping there are super simple to fix and will hold Up to 8kg in weight (more than 12 cans of beer) 
They simply flick the shelf itself and it opens up then pushes firmly down to fold it away ,it doesn't rattle or squeak ... 
The dimensions are 30cm wide x 27cm height with a 6.5cm folded projection and 18cm in use projection
This is definitely something that you never realized that you needed until you have one 
This one is grey with matching  edging
It also comes with instructions and relevant fixings...
Also available in black sparkle with silver edging or grey with silver edging