I have a second question.....I noticed that these Echo lookalike heads that JThomas handles has a slight different release. You can turn the head in either direction to release it. But it is MUCH harder...almost worthless. I hope Echo stays with their present design.if it's on an srm trimmer, it should be a 2150030 head. Push the spool in and turn clockwise, you should feel it pop, then pull off.