The OKM consists of a pair of tiny omnidirectional electret-condenser mics wrapped inside plastic foam screens, making them look and feel much like regular ear bud headphones.
Soundman OKM microphones in detail.
Example applications for OKM mics.
Links to reviews of OKM mics in Stereoplay, Sound On Sound, Electronic Musician...
Answers to common questions about Soundman microphones.
Model comparision chart with prices and specifications.
List of resellers in Finland.