I have a little Beofeng radio and mic and the mic’s are known for their week mic signal so back in August I bought “10x5 mm 30-40 dB electret condenser microphone high sensitivity pickup” 5 pieces for $3.95 including shipping. This item is still available from eBay.
1 I replaced the small pick up with the 10 mm one. (I had to cut away the plastic ring around the small pickup)
2 I drilled a couple more small holes in the microphone face above where the new pick up sits