Silvered Brass Knuckles

Push (Mastery): If you hit a creature with this weapon, you can push the creature up to 10 feet straight away from yourself if it is Large or smaller.

Some monsters that have immunity or resistance to nonmagical weapons are susceptible to silver weapons, so cautious adventurers invest extra coin to plate their weapons with silver. You can silver a single weapon for 100 gp. This cost represents not only the price of the silver, but the time and expertise needed to add silver to the weapon without making it less effective.

Light: A light weapon is small and easy to handle, making it ideal for use when fighting with two weapons.

Proficiency: simple, brass knuckles Source: Player's Handbook (2014) p. 148, Ben Huffman - Pugilist (Third Party)