Switchcraft Microphone Jack 3 Circuit- SWCS12B- JJ-033.
Contact springs are of special alloys for long life. Insulation is high dielectric strength phenolic. Tinned terminal lugs for easy soldering. Short frame. Mounts by 3/8-32 threaded bushing and nut. Open circuit until plug inserted.
Appear to be high quality, have not had a chance to actually use them yet, but they are installed. Im sure they will work great.
Yes, this is the size needed for the small microphone plug that is part of the dual GA twin plugs most David Clark headsets are outfitted with.
Yes, this is the correct mic input jack for dual GA plugs.