[Answered]  LR string launcher spring replacement

While I was launching with my lr string launcher it stopped retracting, so I assumed I just had to reset the spring. However, when I opened it up, I found the spring had snapped in half! So my question is, what size of spring do you need to replace the spring in the TT lr string launcher? Thanks in advance
I don't know the exact size needed. But I should stress, attempting to replace a launcher spring without using a spring from an identical launcher type would make the fixed launcher prohibited for WBO tournament use.