Amazon.com: Digital Camera External Microphone Compatible with Olympus OM-D E-M5 Mark III Digital Camera, XM-L Wired Lavalier Microphone - 20' Audio Cable - for DSLR's, Camcorders, Video Cameras and Smart Phones :
Olympus Sema-1 Microphone Adapter Set 147592 - Adorama
using a rode videomic on a olympus pen camera using the sema 1 microphone set - YouTube
Olympus SEMA-1 Microphone Adapter Set on JEAK - YouTube