Genuine Gold plated TANNOY grade 4mm speaker speakers sockets.
Tannoy did use various suppliers, so occasionally they "sit height" might differ slightly once installed.
Accepts 4mm plugs. Threaded part approx 3.8mm, hole for wire approx 5mm and will accept 4mm plugs also.
DO NOT CONFUSE THESE WITH MANY CHEAP VERY INFERIORS TYPES.