This is a door stopper/holder designed for holding a hinged door open at any desired position.

I attached 1.5mm self-adhesive neoprene foam on the bottom surface. This ensures enough friction to hold the door in place, while allowing it to slide relatively easily when pushed by hand. 

As it is, it fits a 35mm thick door with a 10-15mm bottom gap, but the model can be easily modified to fit most hinged doors with a bottom gap of 6mm or more.