What Size Is Sterling JP50 Tremolo Arm? 5.5mm or 6mm?

Hi super short question I know but, does anyone know the size of the tremolo arm in the JP50? Is it 6mm or 5.5mm? I bought one of these second hand and am trying to find a replacement arm as it doesn’t have one! Also any recommendations for where to purchase one? I’m looking for *chrome* Thank you so much.

Blessings
Dylan