1.08 by 1.08 inches square per instruction with baille;
Sanskrit numerals form the magic square associated with the holy Moon and the number two. Silver is the ideal metal here.
The numbers will touch your skin.
The above rendered picture in silver looks battleship gray for some reason. This is NOT how the item looks in real life. Rather, it looks like a delightful pure light silver, much like the rhodium plated rendering above. (Rhodium is a type of silver.)
Yantras for Venus (silver), Jupiter (silver or gold), and Sun (gold) are also available in this store.
All other grahas ("planets" in Jyotish or Vedic astrology) are available by request.
See the book Numerology by Harish Johari for more information.