Sterling silver metal alloy skull charm . Jewelry, skulls, and rock & roll. The collection Ser imparable is designed to bring out your most punk spirit; a spirit that prefers to ask for forgiveness rather than permission, a spirit that is unstoppable and gives it all. If you are surrounded by chaos and noise with the volume up to the max, Ser Imparable is the collection that will take you on stage like a true rock star.