Joseph
Look at the pics on top of this page
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=14;t=002195;p=4 You can kind of see the «brush rest» and that nylon screw I was talking about. The brush rest is made out of nylon/plastic brushes, kind of like a tooth brush, on witch the arrow would rest.
The burger button, well, not exactly a burger button in this case, is there to adjust the position of the arrow in or out. Comes in handy to fine tune your arrows to the bow. Arrow too stiff, screw out the burger button, arrow too weak, screw in. Or is that the other way around?
Here is a definition I found on google
Button i.e. Plunger, Burger Button—The button is a device that, when the arrow is being shot, prevents the rear of the arrow from overtaking the front. It also aligns the arrow in the center of the bow and keeps it from hitting the bow once shot.
Here is a link
http://www.abbeyarchery.com.au/p/ARTC989/What+is+%85+a+plunger+button.html Simon