In description of product says it comes with nuts and washers. This means there has to be a threat into the encoder so you can use those nuts and washers to mount the encoders (to a faceplate or so). After product arrived it was without threat (and nuts and washers as they are useless for a non-threaded encoder) so it could not be mounted to faceplate. After contacting seller and sending pictures problem was solved, seller was very helpful! See picture for the wrong product being send (one without threat/washers/nuts) Again: seller very helpful solving the issue so I ordered there again (now I hope with threat).
Good transaction. Thanks