The Grand Masters of the Knights Templar during the later 12th and the 13th century used a double-sided seal which showed a representation of The Dome of the Rock (or a circular dome of the Church of the Holy Sepulchre) on one side, and the Order's symbol of two knights on one horse on the other side.
This design is first attested as in use by Bertrand de Blanquefort, the order's sixth Grand Master, in 1158, forty years after its foundation, and it remained in use until the dissolution of the order in 1312.
The seal says in Latin: "The seal of the soldiers of Christ"
 
Hand carved in solid yellow bronze. Signed in the back by the artist.
Patina applied for aging.
Soldered bail on top.
 
The pendant is 25 mm or 1" wide.
Different 14k gold filled and blackened sterling silver chain length and thickness options are available. 
The thin chain is 1.4mm.
The med chain is 2.3mm.
The thick chain is 3.5mm.
Gold filled has 100 times more gold than plated thus does not rub or peel off.
Also, a 4 mm wide black genuine Greek leather option.