The line feeds out automatically maintaining the nylon line at the correct length. To load it open it up and wind the line onto the spool by hand. It takes 20 feet of line, 10 feet on each half of the spool. I used up the line in the head twice and found that .095 line does not do well in the heavy weeds I am cutting. This head will not accept .105 line. I am going back to .105 line in a bump head so do not need this. It comes with 20 feet of Stihl round .095 line. Stihl round line works better than Magnum Gatorline Supertwist. I didnt try any others. It is on EBay http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=230821783229&ssPageName=ADME:L:LCA:US:1123. Current bid is $.99 plus $9.50 shipping. This will probably be a cheap way to get this head if you were thinking about it.