“but what explosive was used”
There is no explosives..the one at CNN had nothing but powder in it. Every bomb expert, military or otherwise, that has looked at these so called bombs say they are a joke...no danger to anyone; also, they would never allow the pictures of the items to be shown at this early date. It’s a hoax and they were sent to all the right people, knowing they would hammer President Trump on it.
If no explosive, why are they calling them bombs?