PivoTrim™ 17080 Hybrid Replacement Trimmer Head, Unique 2-In-1 DesignSick of broken and jammed trimmer lines? Tired of stopping to change broken trimmer lines? That's why we created the super strong, extremely reliable PivoTrim! Tough enough to cut right through plywood The PivoTrim is one of the best home investments you'll ever make! On other trimmer heads, strings exit the head at a fixed point bending and weakening them until they break, but the PivoTrim patented pivot design allows the line to absorb the shock,