GP340 and GP344 radios require the appropriate headset adaptors or in the case of Mckay headsets the relevant PTT lead shwon as an accessory to the headsets

2.5mm Mono, 3.5mm Mono; Right Angle

Distance between pins: 7.5mm

MOTOROLA 2 pin radios: GP300, SP50, P110, P-1225/P1225LS, LTS2000, CP040,  CP88, CP150, CP200, CT150, CT250, CT450, CT450LS, GP308, P080, P2000, PRO2150, PRO3150, P040, P080, GP68, GP88, PR400,SP10, SP21, GTI, XTN446, XTN500, XTN600, PR400 PRO1150, PRO2150, CP100, PMR446, XTN446, XU1100, XU2600