I had to get this spool because I got a used trimmer for way cheap at Sears, but it didn't have the spool. Unfortunately, we then spent an hour or so trying to find a spring that would work for the "bump" feature so that it would actually work properly. Granted, the spring isn't costly, but it's something you should know going into it. If you've got the old spring, go for it. If you don't, you should probably find a spring or a different spool. Over all, it does the job I need it to.
I purchased a Craftsman Weed Whacker, 15" about two years ago. I was excited because it was so much wider than a more common 12" one. Somehow over the course of the winter, I misplaced the string spool to make it function. I went to several Sears stores to find a replacement, but none of them are sold with spring that makes the clutch release when you "bump" the trimmer on the ground. I'm sure the old spring is attached to the misplaced old spool. I tried several Sears stores to find just a spring, then went to another home improvement store and found one - just to come home and realize it is too big... in its compressed state, it doesn't allow the spool to be locked into the trimmer. I solved the problem with some high density foam padding stuffed in the chamber, to give the repacement spool the necessary springiness.
Sears needs to sell replacement spools with the spring inside them. This was way too complicated for something that shold have been straightforward and simple.
Wrong item inside the packaging. I ordered Craftsman 85967 Replacement Bumped Feed and recieved Kenmore 12-cup Permanent No. 4 Cone Coffee Filter