The kicker band hooks onto the SS 16mm extended mushroom head screws (included) which are attached to the bearing rods.It will assist in the initial launch of a heavier 7.5-8mm shaft used on a single roller gun, allowing the shaft to gain greater speed and penetration.Best suited for spearguns in the 100cm-130cm range when hunting large pelagics in blue water. With a 16mm main rubber, a 14mm kicker band is recommended.With a 18mm main rubber, a 16mm kicker band is recommended. Kicker band length is made to order depending upon the length or your gun.