Truss tool for H140

[Picker64]

I have a early 90s H140 and want to tweak the truss rod.What is the proper tool/size? I'm more of an acoustic player and know more about acoustic guitars.What are the specs on this guitar?

[golferwave]

5/16 inch truss rod tool, 5/16" nut driver, or you can use a 5/16" 6 point socket from a 1/4" socket set with a short extension and ratchet.