I think with the mag nocks the magnet was on the arrow to keep weight off the string. I think they had a better hook up system as well.
Paul.
The Magnocks magnet was in the reciever that attached to the string the actual nock had a tiny ball in them.
I used the Magnocks for 3 or 4 years in both hunting and target, never did have a problem with the arrow falling off the string.
I dont think they are still in business.
I still have a couple of recievers and about 2 dozen nocks sitting in my tackle box.