Those things are made/cast from a soft white metal, similar to pewter, or zmac. Not very solid, to say the least. However....if your window regulator, and tracks are dry, or gummy, that could accelerate the wearing out of the splines on the handles. You might try cleaning the regulator gearing, the rollers, and the tracks, and then putting a light grease on them, to allow the windows to go up/down much easier, thereby extending the life of your next set of handles.
Don't know if "Trim Parts" makes the handles, but you could check. If they do, they will be a very good quality.
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Joel Adams
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