Be very careful with those. I used to be a mechanic and I've seen more than one engine ruined by people adding magnetic things. What happens, is that if metal gets near a magnet but doesn't stick to it then the metal gets magnetized. Then as it floats through the oil it sticks someplace it shouldn't. And then instead of getting caught in a filter, it gets caught someplace else...Like a small passage in the engine/trans which blocks part of that passage and starts magnetizing other pieces of metal that float past it, and on and on until you have little pieces of metal stuck all over.