Not needed but wouldn’t shoot without, and +1 to what golddust said or maybe call a local shop and see if they have one kicking around. I had the same problem with the same bow but was able to recover it(thank god as it wasn’t my bow). I use String wax or locktite on the threads on all bolt on parts just to make sure nothing falls off on a hunt and I’d maybe check all attached goodies if you got the RTS model as my dads did attachments/string stop did not come locktited in