KH director help

[LOVEROCK]

Was calibrating probe and it’s leaking so I tighten it more and now the inside lock is spinning when I try to release the probe, what is that small skinny wrench called , wondering what size do I need , also notice the o ring , am I inserting it wrong or is it time for a new o ring

 

[paul01609]

Think it could be a m20 stuffing gland it could be printed on the gland it’s self