I operate mostly CW on my SOTA outings, but I always take this light weight mic along since it's built into my earbuds. This is just a standard smartphone ear bud/mic with an adapter that was intended to allow connection to a computer. Turns out that the earphone and mic jacks on the Elecraft KX2 and KX3 are compatible. To transmit, use VOX, or PTT with the XMT button. Note the essential windscreen. This was made with earbud foam hot glued to the mic housing. Keep the glue away from the side with the mic hole.