Production made CPU port or as I like to call it the shock dampening port 
It was used in the scene where the CPU is going to be reset at the auto garage. Sarah Connor and John Connor open the Terminators CPU port and reset the CPU switch. They basically turn off the Terminator a for a few minutes while they do this. With Arnolds hair peeled back we need the outter most cap which is removed with a air wrench fitted with a slotted screw driver. And next the plug undearneath that, which is removed by a set of pliers. And finally the CPU under all that.
Originally made by Don Pennington, machined metal, vacuum metalized resin base.
First sold by ScreenUsed.com and then Profiles in History.