SIMPLE TO USE,  CUT TRIMMER LINE INTO 8" STRIPS AND JUST PUSH INTO THE SELF LOCKING HOLES ..ANYONE CAN USE THIS. HOW MANY TIMES HAVE YOU HAD YOUR EMPLOYEES COME TO YOU WITH THE TRIMMER SPOOL EMPTY OR IN PIECES?  NO MORE! CITY AND TOWNS, GOLF COURSES AND ANYONE WHO HIRES SUMMER HELP NEED THIS. TRY ONE TODAY.