DM3 microSD™ Card Connectors Hirose DM3 microSD™ Card Connectors are extremely small size devices featuring reverse card insertion protection, effective ground and shield configuration, and rigid and strong construction. The card detection switch is normally open. Hirose DM3 microSD™ Card Connectors include push-push with ejection mechanism,hinge, push-pull, manual without ejection mechanism, and push-pull, manual without ejection mechanism options.