Yantras; Vedic Seals & Talismans

Yantras are mystical instruments that act as great cosmic conductors of energy. They originate from Hinduism and bear a striking similarity to seals and talismans from grimoires such as ‘The Key of Solomon’ which surfaced much later on.

Astroved.com and several other stores sell yantras.

I have a few yantras and was wondering how many of you made use of them. Here are scans found online of planetary yantras for the Sun, the Moon, Mars, Mercury, Jupiter, Venus, Saturn, Rahu & Ketu:

I did not use one of these but I have a Charged Ganesh Yantra in my Wallet.
And used a Shiva Yantra while working with him.

This is a really good book about yantras: Yantra: The Tantric Symbol of Cosmic Unity.

Lots of detailed diagrams and full-colour plates, well worth the money.