Fox T-Bird/Cougar Forums  

Looks like a 1/4 " pipe plug arrangement. Great for the old radiators but the new ones do not have a pipe plug to install it.Does it come in different thread arrangements??? Sounds like a good product. A sacrificial anode. Boats use them very successfully.

I actually don't use that particular anode. I have one that hangs in the radiator cap opening and down into the radiator. A local old time radiator shop sells them. I've yet to replace it but it has deteriorated a slight bit. I do change the coolant every three years though, no matter the mileage.

Edit: Looks like this product but attaches to any radiator cap.

What about all that crumbly nasty shiznit floating around in your coolant and water pump?  Looks pretty abrasive in that above pic.