A more thorough explanation:

Definition: A libripens is a person who holds a bronze balance during actual or ritual sales in Roman law. They are also known as scale-holders.

Example: During the ceremony of emancipating a son from his father or conveying important property, a libripens would hold the bronze balance. The purchaser would strike the balance with a piece of bronze to symbolize completion of the sale. The seller would then receive the bronze as a sign of the purchase money.

Explanation: The libripens played an important role in Roman law as they ensured that the sale was completed fairly and accurately. The use of the bronze balance was a symbolic gesture to show that the transaction was complete. The libripens would also be present during the mancipation, which was a legal formality for transferring property by either an actual or a simulated purchase. The presence of the libripens and other witnesses ensured that the transfer of property was done in a formal and legal manner.