what is this

First off I`m not familair with f-150`s at all. I have a freind who has a 97 f-150 4x4 8cyl. He had a noise under his truck . Upon investigating the noise he found a cylindrical type object which was mounted on an exhaust clamp and attached to the exhaust system . This 4 to 5 inch object has some weight to it but ther are no signs whatso ever that there were ever any wires or connections on it . Any ideas ??
thanks Muff

Sounds like a counter weight that Ford use's to reduce exhaust vibration

Sounds like a counter weight that Ford use's to reduce exhaust vibrationIs that right? That is what it appears to be just a counter weight. I have never heard or seen anything like it. Two questions now. Why would Ford come up with something like that and how important is it??

It is a vibration dampner and is really not needed since aftermarket pipes don't have them.