Some of today’s tools come with grips that are formed of soft material for comfort, but they can wear down or break apart. Other grips are formed of a harder material to be more durable, but those grips may sacrifice comfort.
Replacement grips are available, but tend to be specific to a particular handle and application, such as golf clubs or tennis rackets. These are usually replaced by professionals because of the difficulty and expertise required.
Re-Grip fills the void by providing durability without sacrificing comfort; it can be installed on almost any handle and is easy enough that anyone can add a new grip.