This is the X-DAMP unit that is installed in Tecnifibre rackets, likely not for sale. It's attached to the grip end. It is said to have excellent vibration damping properties. It is originally housed in an elastomer cap. I'm wondering if the effect can be achieved by attaching it to the grip end I already have. However, I think it's not suitable for leather grips. With leather grips, it becomes +10g top-light. This product makes the top-light effect more pronounced.