This is a most unusual piece of vintage printer's type featuring the letter Delta from the Greek alphabet. This letter has been drilled and polished so that it can be worn on a chain while still being useful for printing stamping or used as a wax seal. This piece is 8mm tall and 23mm long. Chain is not included but may be found in this shop at

https://www.etsy.com/listing/103402941/bead-chain-30-inch-length-with-connector