There’s been a small update over at the ‘Airsoft Hand Grenades‘ homepage. It seems that they are tweaking their (rather elusive) design at the moment, but are on track for a release before the end of the year:
We are sorry to say that we have a little delay because a part of the grenade must be redesigned so we estimated October this year as the new release date. Sorry for the inconvenience, we will maintain you updated about the progress of the AG-01. (Airsoft Hand Grenades)