i make my own with egg sinkers like they use saltwater fishin.Take a piece of wire run through the sinkere and bend a loop in it,so it works like the store bought knockers,plug knockers, get your mind out of the gutter.put it on your line hold it tight with the rod let it hit and shazaaam you get your bait back,now if 1 don't work put on another and shake it i have never used more than two and have only lost a handfull of baits,mostly suspend dd's i havn't got back.the sinkers i use are the size of small chicken eggs.i guess you could rig a string on it so you can retrieve it but i don't.