It is a long stick about 18 inches (whatever you need) to help load your motor. The end is such that you can load the end of the rubber into the model and insert your rear peg though the rubber, then remove the stick. Mine is too long for my field box and I apparently misplaced it.
So no picture. NEED to find that before flight season.
Before I had this, I had an access hole in the bottom of each model to assist in this process. I made a stick from a wood dowel as per Don Ross' book, but now I have a manufactured aluminum one (somewhere). I bought this from a vendor at my first FAC contest.
Mitch