The Uni-Loc weight cartridge system has been used on Predator cues since 2008.
If you have a Predator cue that was made before 2008 or before the current Uni-Loc Weight Cartridge System and you need a replacement weight bolt, this weight bolt will fit Predator cues made before 2008. The thread size is 3/8x16 and the head style is flat.
To install one, remove the bumper of the back handle, and you will have access to screw the weight bolt in.