.065 weed eater string. This comes on a 1,800 ft. long spool. A small amount (probably less than 100 ft). of this was used prior to the weed eater it was for broke down. The new weed eater uses a different size string. This sells for new on Amazon for $27.96. See https://www.amazon.com/gp/product/B003VPAEL6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1