Olympus OEM  RM-CB1 Remote Cable Release 

Fits E-1, E-300 (via Power Battery Holder B-HLD3), E-10 / E-20, C-5060 WideZoom (via Power Battery Holder B-HLD20), C-8080 WideZoom (via Power Battery Holder B-HLD30)

Excellent condition 
Olympus RM-CB1 Remote Cable Release for Olympus OM-D and PEN Cameras