Fang Muk / Fang Mook (ฝังมุก buried pearl) are penis implants. Scroll down for a picture I have taken myself and posted before NSFW.
The subject has already been treated elsewhere:
But I recently found a blog in Thai language (with pictures and sketches) and a video about how fang muk is done.
(approximately: "What you need to know about fang muk")
15 July 2015 remove picture (of fang muk taken by myself on 05.10.2014) to comply with google adsense
Copyright 2014 ChristianPFC (except for the video)