This is a 4" adjustable spring bobber (made by Marmish out of Canada) you can use this for micro jigs to catch panfish or retract it in a little to get the best bend out of the spring bobber to detect the bite. This spring bobber also allows you to use a heavier lead or tungsten jigs for crappie and bluegills small trout and salmon because you can adjust the length of the spring bobber from the rod.