These are Radios that we know the connections for the Mic and Speaker ,please tell us the radio you have to make sure you get the correct headset Plug

          
      uniden 040,   pmr500,      digitor ,      digitalker .  custom            GME MC6000  spkr mic    
 
               
        D1793   Dick Smith                        spectra CS800                         Hoffer 505
        2.5mm tip mic, ring spkr                    2.5mm tip mic, ring spkr                        2.5mm tip mic, ring PTT ,sleeve 
                                                                          3.5mm  is PTT                                  common ,   3.5mm spkr  

                                                                                                         
              
  
            Icom     Jr40                      Uniden 041P                           GME TX610 
2.5mm mic, 3.5mm spkr                    2.5mm Tip Spkr  ring mic                    2.5mm mic, 3.5mm spkr 
            
             
          TE1172WT  (warehouse!)                           Watch talker    from jaycar etc BinaTone Trek 100.
        2.5mm tip mic, ring spkr                           3.5 mm, tip mic, ring spkr,  sleeve common.

                                                    
     PHSL    WT419  ( water resistant!!)           Nady MRC-11                                              the new   Uniden 043 !
     2.5mm tip mic, ring spkr 3.5mm PTT     3.5mm  stereo plug with sleeve            2.5mm tip spkr, ring mic                                                                                                             earth, ring microphone and tip spkr      .      built in intercomm!               .              also 041/047/060  same plugs!
   separate 3.5mm for PTT

Motorola T5720 ,Tip spkr ring Mic   oricom PMR1000 2.5mm  tip spkr, ring mic.   GME TX630  2.5mm mic, 3.5mm spkr ,  Binatone 3.5 mm tip mic, ring spkr

                         
Yaesu VX5  3.5mm stereo, tip mic .   Digitalk SP 808 and  SP103   tip mic ring spkr 3,5mm      GMETX650 tip mic ring spkr 3,5mm 
                                     
PMR1000                                                                        hole  opened with 5.5mm drill           Uniden 044SX  is the same headset as a Uniden 041/43/47/60/61/64
2.5mm  tip ,spkr, ring mic, sleeve common 

Headsets to suit  Motorola Talkabout 270, 280, T289, T5100, T5200, T5300, T5320, T5400, T5410, T5420, T5600, T5620, T5700, T5710, T5720, T5800, T5820, T5950, T6200, T6210, T6220, T6250, T6300, T6310, T6320, T6400, T7200, fr50 and fr60 radios. 
all these radios take a 2.5mm ,right angle plug, " tip spkr,ring mic.sleeve common "

With some models of Motorola T,,,,, series , the headset doesnt appear to work or if you plug it in it feels loose and may fall out  also you may see the radio goes to transmitt  without pressing the button . This is usually due to the  plastic case of the radio holding the plug out ( motorola use a slightly longer earphone plug to make allowance for the thickness of the case ) if you carefully drill out the plastic case so the plug can nestle through to seat on the rim of the 2.5mm jack all will work . Drill out the hole using a 5.5mm or so twist drill  spining it with your fingers , on no account use an electric drill it will grab and drill thru the socket and wreck things ...you have been warned !! 

Headset for Hoffer GS100/ Challenge Activate GS100   is  3.5 mm tip mic ring speaker sleeve earth.