Boston   speaker plug, female, 4-pole

Boston   speaker plug, female, 8-pole

Boston   speaker chassis conn, 4-pole, male, rectangular model 25 x 30mm

Boston   speaker chassis conn, 4-pole, male, round model 50mm diameter

Boston   speaker chassis conn, 4-pole, male, square model 40 x 40mm

Boston   speaker chassis conn, 8-pole, male, square model 40 x 40mm