ACDelco Cooling System Sealing Tabs - 4 g 10-108

I'm always skeptical about products like this but figured I would give it a try as it had good reviews. Walmart had the lowest price so I bought here. used in two different vehicles with two small but different coolant leaks. put all the pellets in the overflow tank when cold and within a week or two both leaks on both of the cars were sealed. so far several months in and still no leaks