I am actually getting ready to make my own snap on system.
I had purchased some Leader Grip side tension grips a while back at MQX East and was using some pieced flannel for my backing. I managed to break the snap on piece on the sewn seam and needed to replace/fix what I broke.
I decided that some smart person had to re-purpose an already made item to create these, SO ... I went in search of what they were - and found on another quilting forum that for the Leader Grip - the snap on pieces they were nothing more than a Rope Lighting Track!! These are sold by Amazon and like sites for $2.40 for a 4 ft length. I just ordered 6 of these and am off to a Home Depot to purchase some tubing that will fit them. It is identical what the Leader grips used and for a fraction of the cost.