A trimmer head for a rotary trimmer machine includes a housing having a recess, a trimmer line spool removably mounted in the recess, at least one exit opening on the housing wherein trimmer line wound on the spool passes through from within the housing, and an eyelet disposed in the exit opening. The eyelet includes an open area leading into a slotted area, said open area being normally closed by a pivoting gate biased into the closed position, and movable to an open position allowing trimmer line to move through the open area past the gate into the slotted area. The trimmer line spool is reversible so that when installed in a first configuration, the trimmer head may be installed on a clockwise rotating trimmer machine, and when the trimmer line spool is installed in a second configuration, the trimmer head may be installed on a counter-clockwise rotating trimmer machine.
