Cool Bomb! I use vibranium a lot. This is one of my favorite projects using vibranium! Good job man +1
Why the c4 is there: when the c4 explodes, it is a signal meaning that it is halfway through its "incubation". Also, it creates more pressure and heat so the TMP of the VIBR is increased just a little bit! It may sound unnesasary, but thats how it melts things! One job, if it's done well, means a lot! P.S. The flashing indicates the time it will take to explode, too.