Oh lord, it's finally out. I thought that after our first very delayed grenade launch, we'd have gotten this one right. We're finally in production!
http://airsoft-innovations.com/Impact.html
A single impact grenade is tough enough. A timer-impact is out of my league. There's no way I'd be able to do that in an affordable manner. Jessica Alba? Bring me Jessica and I'll make you a timer impact grenade.