Works as advertised. You have to take one end of the cable(s) loose to slide the new clip over them, but the self propelled lever works better with the cables properly routed (take the time to lubricate the cables while you are at it). Do your trimming first and then you won't be tempted to get too close to the house, shed, fence, etc. and break these off the mower. Plus the trimmer clippings will get mulched up by the mower and your yard will look nicer.
I replaced these on a coolish spring day. Ensure the plastic is warm before you install them as they have to flex and you don't want to break them. Hint: run them under some warm water for a minute first so they will bend easier.