A trimmer head for a trimmer having a shaft defining a rotation axis. The trimmer head comprising a housing including a main housing and a lower cover, and wherein the main housing contains a pair of opposed eyelets through which trimmer line is discharged. A spool encased within the housing, with a bump knob connected thereto, and having a passageway with opposed ends and extending from one side of the spool to another, the opposed ends being alignable with the eyelets to receive the line. A first set of a plurality of ramps located on an inside surface of the main housing and a second set of a plurality of ramps located within a center barrel of the spool. The two sets of ramps interact to control the direction of releasing line from the trimmer head and forcing indexing of the spool when the bump knob is bumped.
