Te idea is to create a new item, similar to an explosive charge, crafted with ductape, a clock, an grenade (explosive or flash), and a gas canister. Depending on the size of the gas canister the explosion would have a diferent damage, small would be the same as 2 explosive grenades, the mediun 4, and the large 6. The craft wouldnt need the grenade, since it would have a slot, same as the trip wire, to add it. before adding the grenade you would need to set the alarm, so it explodes when the clock rings.