The Uni-Loc weight cartridge system has been used on P3 cues since 2008, and then used on all Predator cues introduced since 2008.
If you have a Predator cue that was made before the current Uni-Loc Weight Cartridge System and you need a replacement weight bolt. The thread size is 3/8x16 and the head style is flat. You can find it in a local hardware store or you can order it from our website here:
International Customers: https://www.predatorcues.com/int/predator-pre-2008-weight-bolt.html