[Elecraft] K3 - 3.5mm plugs

[K5WA]

I know this may sound silly but does anyone know the exact/best
specification for the correct plugs to plug into the 3.5mm jacks on the back
(such as the phones, mic, speaker, line out, line in)?  I have purchased
several over the years and I guess I'm buying really cheap ones because they
seem to be losing contact with the jack and I'd like to buy the "right" ones
to get good connections.

Thanks,

Bob K5WA