On the rear of the unit is a single threaded hole.
Sometimes used to mount a guide pin or dowel depending on the car.
Does anyone know the size and thread pitch of this.
It's next to the fan.
Is it M5x6 like the ones on the side?

I want to use it as an anchor point for an anti-theft steel cable.

Thanks
-Rick

Credit to "listen2mp3" for this gianormous hi res photo.

that hole is on most pioneer units. on regular sing-din units, it comes wit this 5 or 6mm bolt that goes for the hole. itz usually meant 4 a ground, if the wire harness doesn't have 1. u could use a backstrap n bolt the z1 down n drill the other side to ur chassis.