Are these encoders or its something else?

Parts Questions
1

Will these cute things work? http://7894.ukrindustrial.com/cat.php?cs=

http://www.apeiron.kiev.ua/sensors/displacement/rotative.htm

Are these encoders or its something else? Yet, hadn’t found knobs to stick on encoders (am i rigt?)  

2

I don’t know, I don’t speak Russian??

Try asking in the Russian forum.

3

http://www.gefran.com/files/prodotti//8ec05357-8f27-4ee2-b4d0-3a80e2544425_ds_PS_ing.pdf

Greets, Roger