As for the Tantric instruments, if they are newly made, they are only counted as handicrafts. If it is from the past, someone must have practiced it. For us, its function is equivalent to a top-level home feng shui product. It is usually placed in a clean place. As long as it is played with joyfully and often, it is good. It can also be used to burn incense and make offerings respectfully. You must not practice Tantric Dharma casually, because Tantric Buddhism has strict teacher-to-teacher rituals and practice sequences. Practicing without the permission of the Dharma master is bound to the Vajra Hell.
Speaking of effects, does your vajra make you happy? If so, that's best. In the past, copper itself was a precious metal. Whether it was Han or Tibetan people, the ancients often used copper to make heavy tools. They did not collect scrap copper and iron from everywhere in today's society and resmelted it for secondary casting and secondary use. One is heaven, earth, human beings, and the other is full of troubles. With different origins, there is a natural distinction between superiority and inferiority.
So we have an ancient bronzeware, which is a blessing. We should cherish it, be happy, play with it and appreciate it often, and don't let it be lonely. At least it will not lie to you or harm you.