This is made to accomplany your grip guide (version B) to make sure that the guides do not wiggle as you install your grips. Place your grip guide on the bottom of the pommel and slide this over the top and lock it into place. This is spaced for 6 grips on The Force Awakens (Rey version) lightsabers.
PLEASE NOTE: This is designed only to work with Grip Guide Version B for ESB/TFA lightsaber installs. Specifically it is designed for 13.3 mm wide grips that are 92mm in length, such as Wannawanga grips.