My dearly departed Dad left us a spool of .080 the size of a battleship gun round, so this should last us our lifetimes! LOL. Our pootie little Ryobi 18V weed-eater bit the dust, so we got a 2nd hand 40V Black & Decker that cautioned "only use .065 line". Well, our donor also gave us pre-wound spools of that size, but I could not rewind the empty ones with the thicker plastic line, so I awl-ed out the keeper hole and slot to accept it. Tried it and it works absolutely fine! I did Dremel sharpen the cutter blade on the housing after a nice scraper cleaning. BTW & fyi, those pre-wound spools are kept in place with reinforced packing tape, so it takes longer to remove that mess than to simply wind your own, like I did from dear ol' Dad's "barrel-O-trimmerline"! Hope that helps Y'all.