You get Gold Colt 45/45's with Ivory Grips, Nickel Plated Luger/Lugers with Rosewood Grips, and Gold Knife/Knives with Ivory Handles. Firepower, Capacity, etc. are unaffected, this is only a skin pack.
The Pistols will work for single, dual, and silenced modes.
Knives work drawn, thrown, and lying around in the game, if your Mod supports this.
Depending on your Mod you may see Gold magazines and/or Gold Silencers for the Colt/Colts, same with the Luger/Lugers in respect to Nickel Plating.
You also get an ingame cursor to match the knife.