This is a Re-Mix Mixup of Devin Montes' Extruder Knob and graham01's Extruder Cover. 

Devin's knob is here:

https://www.myminifactory.com/object/manual-filament-feeder-knob-mod-for-cr-10-and-other-bowden-3d-printers-52492

graham01's cover is here:

https://www.thingiverse.com/thing:2456930/#files

I simply used the knob to cut a hole in the cover, and this is the perfect combo for me.

Not only does the knob help to load and unload the filament, but it also gives you a visual cue when the filament is moving. The cover keeps all dust and dirt out of the Extruder and helps to hold the wires in place.

I printed both at 0.2 and no supports.

NOTICE: Be sure to install the small piece of Bowden Tube as shown in the photos. That will make it so you can print Flexible Filaments without issues. And it also helps with normal filaments.

NOTICE: It has been commented below that this may not fit the newer CR-10 with a black extruder. Please verify before printing.