Do you want to improve your guns accuracy allowing the spear shaft to smoothly leave the guns stock with less wobble and a straighter path? Tru-Glide Rail is used to assist in keeping the shaft in place without slowing down its speed. Kitis designed for the Explorer and Carbine Series Spear Guns (4D22, 22L and D-7's)and is easy to install. So if you are looking for increased accuracy and keepingyour spear shaft properly in place be sure to install the Tru-Glide Kit.