Similar to the Sampras one, but better in my opinion since the Sampras dampener will eventually change shape from circle to oval by the strings if you have a denser main string pattern. This one wouldn't.
This damper works perfectly for me. I use it on my 100L Pro Staff racquet. It absorbs any vibration and give my racquet a nice solid comfortable feel. I would strongly recommend it.
Works like a Champ! Immediate change