How do I repair stun baton?

[Bill the Butcher]

Says I don't have the required materials but I can't see what materials I need.

[Shurenai]

Icon of what you need to repair it shows up in the bottom right with a little X icon indicating you don't have it. Most likely it's a repair kit.

[Ogami]

Normal baton repairs with "short iron pipe", the stun baton repairs with a "repair kit" like all non pipe weapons.

[Bill the Butcher]

Ok thanks.