use the silver one on the handle side to set the tension on the spool,set it so the spool runs freely,whilst adjusting move the spool from side to side until there is the minimum amount of play.use the knob on the left to control the speed that the spool runs,best to set it on slow have a cast and see how it goes out,then adjust it a little each cast so that it goes out smooth without the line lifting off the spool......hope this makes sense and helps you out.
cheers sean.